Pervasive Retail Part I: Web UX Meets Retail CX - Screens Large and Small at the Mall, Revisited

If you follow my blog(s), you know that I have a passion for interactive displays in public spaces, and that I enjoy watching how various technologies converge, jump across platforms and devices, inter-operate, and re-purpose over time.  

The best places for watching this unfold, in my opinion, are airports, malls, shopping districts,  and larger "big box" establishments, where the Web meets Digital Out of Home (DOOH), old-fashioned kiosks morph into multi-touch screens and gesture-based windows, and visual merchandising meets technology, digital culture, architecture, and consumer metrics.  At the center of it all is the user/consumer - regular people, moms, dads, kids, teens, the elderly, the disabled, the hurried and the worried. Adding to the complexity is that an increasing number of people who are out-and-about are tethered to various mobile devices.

In scholarly tech circles, the concept of DOOH is known "Pervasive Retail".  The explosion of mobile devices and ubiquitous screens has fueled the fire for research, and is the focus of the current issue of IEEE's Pervasive and Ubiquitous Computing.   

Despite the influx of technology, no-one is exactly sure how to do it quite right.  (I have some ideas, which I'll save for a future post.)

If you are interested in learning more about concepts related to "pervasive retail", the Retail Customer Experience website is a treasure trove of information related to DOOH, digital signage, multi-channel retailing, in-store media, kiosks, interactive touch screens and windows, related metrics, and more, with stories about real-life technology implementation.

Mall Video

The following video, taken with my handy HTC Incredible, provides a quick sampling of the screens I encountered during a recent visit to South Park Mall, in Charlotte, N.C.  The last screens in the clip were taken in the Brookstone store, and will be included in another clip that focuses solely on all of the screens that were scattered about the retail space.  

I have a hunch that some of the smaller displays in the Brookstone store were iPads.  iPads and tablets have great potential for use for shelf-level in-store interactive visual merchandising deployments, given the right apps and mounting systems. (See iPads as Cheap Digital Signage, by Tony Hymes of DOOHSocial and the video about Premier's iPad mounts, for more information.)

Much of what you'll see in the following video, taken at the same mall in December of 2009, wasn't around during my most recent trip:

Screens Large and Small at the Mall

Interactive Coke Machine and Kid at the Mall

I was sad to see that the interactive screen on the Coke machine  had been replaced by an ordinary one.  Part of the problem, I think, is that the interactive display was too busy and as a consequence, made the goal getting a quick drink a bit too complicated for the average thirsty customer, as seen in the video below:

Touch Screen Coke Machine at the Mall: 90 seconds to get a coke!

RELATED

Previous Posts:

What is DOOH and Why Should We Care?

Quick Link:  Bill Gerba's Updated Graphic of the Digital Signage Ecosystem

Digital Signage and Digital Out of Home (DOOH), via The Digital Signage Insider, Digital Signage Today, and more

Interactive Visual Merchandising, Interactive Window-Shopping at Nordstrom, Downtown Seattle:  "Writing with Light"

Window Shopping in the Web Outside:  Interactive Window Displays (videos and links)

Close Encounter with "Best Buy On": Example of a multi-channel marketing approach using in-store media and an online magazine 

Video: Gesture Interactive Window Display at Repetto Store in France, by the Marcel Agency
Interractions (ACM) Cover "Proximic Interactions: The New Ubicomp?"; Plus - Close encounters with displays at the airport and JC Penney. (Briefly touches on the topic of accessibility/usability/universal design of displays in public spaces, an area in need of further research.)

The World Is My Web Browser: Interactive Technology in Public Spaces

References and Resources (Partial List)

Fujitsu's Pervasive Retailing (pdf)

Ron Brunt, InTouch with Retailing Whitepaper, 1/15/06

When all the world is a screen

Brian Monahan, IPG Emerging Media Blog, 4/15/11

When all the world is a screen (The video is worth taking the time to watch.)

Narayanswami, C.,  Kruger, A.,  Marmasse, N. Pervasive Retail, IEEE Pervasive Computing

April-June 2011 (Vol. 10, No. 2) pp. 16-18 1536-1268/11/$26.00 © 2011 IEEE 

References from the Pervasive Retail article:

Mobile Retail Blueprint, Nat'l Retail Federation; www.nrf.commodules.php?name=Pages&op=viewlive&sp_id=1268 .

G. Belkin, Pervasive Retail Business Intelligence, Aberdeen Group, Apr. 2010; www.slideshare.net/AxiomConsultingAustralia pervasive-retail-business-intelligence .

R. Wasinger, A. Krüger, and O. Jacobs, "Integrating Intra and Extra Gestures into a Mobile and Multimodal Shopping Assistant,"Proc. 3rd Int'l Conf. Pervasive Computing (Pervasive), Springer, 2005, pp. 297–314.

A. Meschtscherjakov et al., "Enhanced Shopping: A Dynamic Map in a Retail Store," Proc. 10th Int'l Conf. Ubiquitous Computing(UbiComp 08), ACM Press, 2008, pp. 336–339.

C. Stahl and J. Haupert, "Taking Location Modelling to New Levels: A Map Modelling Toolkit for Intelligent Environments," Proc. Int'l Workshop Location- and Context-Awareness (LoCA), LNCS 3987, Springer, 2006, pp. 74–85.

Cross-posted: The World Is My Interactive Interface blog

About Digital Out of Home

"Digital out-of-home (DOOH) advertising is a dynamic, fragmented, and rapidly evolving space. It's one of the fastest growing media channels, with year-over-year growth pegged in the double digits through at least 2011....as with many emerging media channels, DOOH is a bit of a gray area in terms of what type of agency should own strategy, planning, and buying. A traditional agency because TV spots can be repurposed? The OOH shop because it's just a digital version of a billboard? The interactive shop because it's digital, often interactive, and highly measurable? Or will a new class of DOOH specialty shops emerge to deliver services explicitly for the channel? This lack of clarity creates uncertainty and
hesitation in advertisers."
-Jeremy Lockhorn, ClickZ  7/13/09 Digital Out-of-Home Landscape Brief (pdf)


This is an industry that is beginning to take off, just as internet-based advertising and web-design/user experience did during the 1990's. The number of players, and potential players, is growing.


For more information, resources, and links, see the rest of the post:  What is DOOH and Why Should We Care?
(The World Is My Interface)

Convergence: Mobile content, Interactive Displays, Digital Out of Home, & Danoo

Danoo: "Location scouting and scalable web technologies combined to create a targeted DOOH experience".

If you are tech-savy and a member of the digital signage/interactive display/AV end of things, you probably know what this means. If not, you should. Things are pairing, merging, and converging in the world of "out and about" technology.

Technology, especially digital signage, is ubiquitous, and has targeted you and your neighborhood.

So what's the fuss? A company from Danoo, from China, is ramping things up in the Digital Signage/DOOH (Digital Out of Home) arena. Fast.

Danoo has rapidly up with exisiting companies, such as National CineMedia, Blue Bite, Electronic Arts, and the HISTORY channel to create and push off-the-desktop and off-the-TV content and interactive user experiences. Bill Gerba, of Wirespring, and Manolo Almagro, CTO of Show + Tell in NYC (think Times Square digital signage experiences), and others have recently written about this phenomenon, right after Danoo released the following press announcement:

Danoo Inc Announces a Breakthrough in Mobile Content Delivery (7/11/09, Business Wire)
"Danoo partnered with mobile technology company Blue Bite to enable the campaigns, and is actively rolling out its mobile interactivity capability to all of its venues. The first 200 Danoo locations will be live in Los Angeles and New York by July 1^st. At full deployment, Danoo will give advertisers the ability to get their content into the hands of more than 200,000 consumers in an average two-week campaign. In addition to content downloads, Danoo offers multiple ways to pair its screens with mobile interactivity to maximize campaign effectiveness, such as SMS call-to-actions, social gaming and mobile application promotion."

"Visitors to Danoo locations viewed video content on Danoo’s digital screens accompanied by an on-screen prompt to download exclusive content such as sneak peeks and ringtones from their Bluetooth or Wi-Fi-enabled devices via the Danoo network."



Here are a few related articles:
How Significant is the Danoo-IdeaCast-National CineMedia Deal?
(7/14/09, Bill Gerba, Wirespring)
A Watershed Moment for DOOH Media
(7/12/09, Bill Collins, Daily DOOH)

Pictures from Danoo's Website:
Danoo's IdeaCast- "Captive TV".


I've probably encountered Danoo's technologies numerous times, judging from my archive of pictures of displays and related technologies that have crossed my path. The TV screen on the treadmill looks just like the one I saw on a treadmill in the fitness center of a Princess cruise ship last year. The picture in the middle looks like it was taken in an airport. The picture on the right is of a system in a coffeehouse. According to information on the Danoo website, the system is interactive and includes "content downloads, social gaming, mobile couponing and more via SMS, Bluetooth and Wi-Fi".

Blue Bite's website is worth looking at. It demonstrates their concept very well through animation:

Blue Bite: "Take the Ad With You"



Things are ramping up in my region, too.
T1 Tapas, a restaurant north of Charlotte, N.C., in the Birkdale Village in Huntersville, has majority owners with a technology background. Mike Feldman and Jim Morris started up Digital Optics Corporation, which focused on optics for computers and imaging, and after they sold their company, they teamed up with Denise Feldman to establish their company.

T 1 Connection Booth with Multi-User Touch Screen, HD TV, Sound System, Computer, & more:

"T1 Connection Booth seating gives you access to music, photos, and videos through built-in touchscreen tabletops, brilliant monitors, speakers, and computers." -Picture and taken from the T 1 Tapas website

The restaraunt serves as a test bed for T 1 Visions to try out their software and hardware designed to enhance the digitally connected dining experience. The restaurant was featured in May of this year on CNN:

Here is the link to the video: "High Tech Tapas"

Saturday Quick Links: Digital Signage and Digital Out of Home (DOOH), via The Digital Signage Insider, Digital Signage Today, and more

The links:

Walmart and Microsoft Talk Up Digital Signage at the NRF
Bill Gerba, The Digital Signage Insider, 1/14/11
Wirespring


NRF: Walmart unveils ROI data for in-store digital signage campaigns
James Bickers, Digital Signage Today, 1/10/11


"C-Tailing" (Converged Retailing)  - NCR
NRF: Convergent technologies on the retail horizon
Cherrhy Butler, Digital Signage Today, 1/11/11

RELATED
Connecting Your Business to Devices and Customers with Windows Embedded

View more presentations from Microsoft Windows Embedded.
Barb Edson, Sr. Director of Marketing, Windows Embedded

Here are a few resources related to this topic:

4th Workshop on Pervasive Advertising (topics)

The Web Outside: Exploring place-based social media 

(LocaModa blog)

LocaModa's whitepapers

Blogs:

Digital Signage Today

Daily DOOH

The Digital Signage Insider

COMMENT
Designers and developers need to think about off-the-desktop technologies as a new form of the web/internet.  Information architects who understand interactive media/transmedia, cross-display/device, cross-platform, and interaction design within a broader context are sorely needed in this space.  


The presentation below, by Chris Thorne, Lead Information Architect and User Experience Consultant working for the BBC, provides a good overview about this topic:

Ubiquitous IA (Information Architecture): Building for change and web 3.0 

View more presentations from christhorne.
Chris Thorne

Stay tuned!

Over the past months I've been gathering video and photos of my encounters and interactions with digital signage as a consumer/customer/user during my every-day activities such as shopping, traveling, vacationing, and so forth, which will be included in a post or series of posts in the near future.   


I have content related to interaction with various QR tags,  interactive kiosks, interactive displays and TV on a cruise ship, an interactive touch screen at J.C. Penny, and more.  If you are a regular reader of this blog, you know that my interests include user experience of DOOH, interactive displays in public spaces, and so forth.  


Note:  Despite all of the technological innovations in this converging field, issues related to context, usability, and accessibility are not consistently addressed from a broader systems point of view.

"Does TV Content Work on DOOH" - Words of Wisdom from Bill Gerba

Bill Gerba blogs about DOOH, which stands for "Digital-Out-of-Home", focusing on displays and kiosks in public spaces that offer dynamic and/or interactive content, usually for the purpose of advertising and marketing.   If this is an area that interests you, take a look at Bill Gerba's most recent post, "Does TV Content Work on DOOH?  Maybe, Maybe Not" - WireSpring: Digital Signage Insider (9/24/10)


Gerba refers to a "Marketing Funnel" graphic to illustrate some of his points.  Six of the seven concepts represented in the graphic, shared below, might be useful to think about for people working in the field of public displays for purposes other than advertising or marketing:





Most of us have noticed that there are many more large-screen displays around.   Some displays intrusively attempt to grab your attention through loud and garish informercial-like content.   Some are designed to be interactive and pleasant, but go un-noticed by passers-by at all!   


There still is a long road to go.


The good news is that a small (and growing) number of scholarly researchers are focusing their attention to displays situated in public spaces, as mentioned in my previous post, "PD-NET Project: Exploring large-scale networks...of pervasive public displays."

Bill Gerba's Words of Wisdom about Digital Media Content (Via Digital Signage Insider)

In this article, Bill Gerba, of WireSpring, discusses his approach to testing digital signage content.  The article is one in an on-going series of articles:


Testing Digital Signage Content: The Need for a New Approach
Bill Gerba, Digital Signage Insider, 3/24/11


From what I've seen regarding the digital signage and displays when I'm out and about,  there is a need for folks in this industry to heed Bill Gerba's advice!  FYI: I've embedded a slide show at the end of the post that includes over 200 shots of digital signage and related "DOOH".


RELATED
Digital Signage Screen Placement:  Targeting the Attention Zone 
Bill Gerba, Digital Signage Insider, 12/17/09

• Digital Signage Screen Placement: Understanding Store Layout
• Digital Signage Screen Placement: Angle, Height and Text Size
• Digital Signage Screen Placement: Modeling Consumer Behavior

Making great digital signage content: Composing shots and scenes
Bill Gerba, Digital Signage Insider, 5/15/08


Lots of "DOOH"

Close Encounter with "Best Buy On": Example of a multi-channel marketing approach using in-store digital media that includes an on-line magazine.

Over the next 9 months or so,  I'll be in the market for a computer, an iPad or something similar, a Kinect, and maybe a mid-size Internet-enabled HDTV.  As a consequence,  I turned in to  a Best Buy on my way home from work Friday to see what I could find.  I didn't want to spend much time at the store, since I'm the type of shopper who goes in, finds the desired item(s), and leaves.  


During this trip to Best Buy, my shopping habits were broken, at least temporarily.  I found myself wandering around, looking at the numerous displays of all sizes located about the store.  The displays distracted me from my intended mission.  Below is a slideshow of the pictures I snapped as I wandered about Best Buy:

As a result of the displays,  I spend more time in the store than I'd planned. I left the store empty-handed.  But that is OK, since I think that this strategy, in the long run, will have the power to entice me back to the store and leave knowing that I've made an informed purchase.


According to Gail Chiasson in her Daily DOOH post,"Best Buy's New In-Store Network", Best Buy established an internal advertising and editorial team in 2009, and officially launched a multichannel network called Best Buy On, which extends the in-store network of displays, to the online magazine, also called Best Buy On .   Best Buy On focuses on different theme each month. This month's theme featured all of the cool things that were unveiled at the recent Consumer Electronics Show. 


The bottom line with in-store DOOH is that customers are provided with with enhanced information about various products in each department, and this information is coordinated with the enhanced information they can access on-line.  Put together, this might lead to better sales,  and happier repeat customers in the long run.  


As I went about Best Buy,  I thought that it would be better if the in-store network of displays was less disjointed.  I also was puzzled by the somewhat inconvenient placement of some of the displays.  People who stand in the middle of an aisle to look at a screen block the view of the screen and the other items on display, and also block the paths of other shoppers!


Although I didn't spend a lot of time scrutinizing the content on all of the screens I encountered, what I did look at gave me the impression that there is need for improvement.  Pretty multimedia content might be attractive to the eye, but if it doesn't  meet the needs of customers in specific departments, it might not be effective.  


Here is a personal scenario:
My 80-year-old mother needs a new laptop and would also like to find an eReader that is suitable for someone her age.  She needs a new printer and is thinking about getting a digital camera.  She has some money to spend, but from what I can tell, she'd be a little confused by all of the flashing screens!  


I'm not sure what my mother would make of the displays, especially those that run animated comments about products from Facebook fans!


(Note:  I plan to go with my mom to Best Buy soon, and I'll share this experience on this blog in the future.)


Although there is room for improvement, the Best Buy On approach is a start.   I would like to see more touch-enabled displays as part the in-store network, given the fact that Best Buy sells touch-screen gadgets, tablets, and all-in-one PCs.   The large-screen touch-enabled displays could provide customers with an Amazon- like advisory feature.  This is something that would be very helpful to my mom and other non-geeks.


Best Buy also needs to get the Kinect demo up and running!


RELATED

FAR OUT 1/9/11 (Best Buy On video about products at CES)

What is Best Buy On?  (Description of on-line magazine)
Best Buy Addresses High-Tech Obsolescence
Shirley Brady, Brand Channel, 1/18/11
Buy Back Program from Best Buy Helps "Future-Proof" Today's CE Purchases
Jeremy Baier, Best Buy, 1/10/11
"Best Buy CEO Brian Dunn describes the consumer electronics retailer's just-launched Buy Back program as "a game-changer." The goal: to help customers embrace new technology with greater confidence."

PD-NET Project: "Exploring..large scale networks of pervasive public displays..."

I love the concept of interactive, networked public displays!   The PD-NET project has a fairly new website and a Facebook page.  If this interests you, take the time to learn about the PD-NET project, a collaborative effort between researchers from several different universities in Europe. I'd like to see this take hold in the US.  


PD-NET Project Objectives (From the PD-NET Website):

• To create enabling technologies for large-scale pervasive display networks through the design, development, and evaluation of a robust, scalable, distributed and open platform for interconnecting displays and their sensors.
• To establish Europe as the international centre for work on pervasive display networks.
• To address key scientific challenges that may inhibit the widespread adoption of pervasive display network technology:  Tensions between privacy and personalization, situated displays, business and legislative requirements, User Interaction.

Here is a list of participating universities and researchers, taken from the PD-NET website:

Participants from Lancaster University (UK):

Nigel Davies

Adrian Friday

Rachel Cooper

Hans Gellersen

Sara Clinch

Participants from University of Duisburg-Essen (Germany):

Albrecht Schmidt

Florian Alt

Dominik Bial

Participants from University of Lugano (Italy):

Marc Langheinrich

Nemanja Memarovic

Ivan Elhart

Participants from University of Minho (Portugal):

Rui José

Nuno Otero

Publication

J. Müller, F. Alt, D. Michelis, and A. Schmidt, "Requirements and Design Space for Interactive Public Displays," in Proceedings of the 18th annual ACM international conference on Multimedia (Multimedia 2010), to appear, 2010.

COMMENT

If you are familiar with this blog, you know that I am passionate about interactive displays, especially in public spaces.  I've devoted numerous posts to this topic on this blog, and also on  The World Is My Interactive Interface, a blog I started a few years ago when I was working on projects for large interactive displays.  


I am interested in how interactive displays, of any size, can be accessible and universally designed, especially those that can inter-operate with mobile devices, including devices that support communication for people with special needs.


SOMEWHAT RELATED
Here are links to some of my previous blogposts related to the topic of interactive displays in public spaces.  Some have links to scholarly publications.  
What is DOOH and Why Should We Care? (DOOH- Digital Out-Of-Home)
Interactive Displays and Interaction (Presentation via Daniel Michelis)
Thoughts about technology on a cruise ship, and other reflections
Multi-touch and gesture interaction out-and-about
UPDATED: More News, Videos, and Links about Multi-Touch and Screen Technologies
Technology-Supported Shopping and Entertainment User Experience at Ballantyne Village:  "A" for concept, "D" for touch screen usability.
Usability/Interaction Hall of Shame (In a Hospital)
Think Globally, Act Locally:  Exploring the Problem Space - Top-down, bottom-up, local and the global...

Touch-screen Interaction at Digital Bus Shelter - Video via Daily DOOH

JCDecaux Innovate Touch-Screen Bus Shelters
Chris Sheldrake, Daily DOOH (Digital Out of Home) 12/2/09

RELATED
The World is My Web Browser: Interactive Technology in Public Spaces
(Watch the video of the interactive "Splat the Cadbury Creme Egg" game played on a large touch screen display at a bus shelter.)

JCDecaux Innovate - Gorillaz for Bus Shelters

Interactive Displays and "Billboards" in Public Spaces; Pervasive Displays 2013

The 2013 International Symposium on Pervasive Displays (PerDis 2013), recently convened  in Mountain View, California.  Since I couldn't attend this conference, I was happy to learn from Albrecht Schmidt that the conference proceedings were recently uploaded to the ACM Digital library.  There are many exciting things going on in this interdisciplinary field!

Researchers involved with the Instant Places project, described in the video below, presented their work at PerDis 2013. The Instant Places project was part of PD-Net, a series of research efforts exploring the future of pervasive display networks in Europe. (See the "Related" section for additional references and links.)


Instant Places: Tools and Practices for Situated Publication in Display Networks

Below is information from the Instant Places video and website:
"The video describes a novel screen media system that explores new practices for individual publication and identity projection in public digital displays." 

"Instant Places has been developed by the Ubicomp group of the Information Systems Department, at the University of Minho, and has been funded within the scope of pd-net: Towards Future Pervasive Display Networks, by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 244011."

Saul Greenberg was the keynote speaker at PerDis 2013.  His keynote, "Proxemic Interactions: Displays and Devices that Respond to Social Distance", highlights how far off-the-desktop our digital/physical lives have become, and how this has influenced recent research in human-computer interaction. Saul is a professor at the University of Calgary and leads research in Human Computer Interaction, Computer Supported Cooperative Work, and Ubiquitous Computing.

Although the video of Saul Greenberg's presentation below is not from PerDis 2013, it touches on the same topics and is worth taking an hour to watch.  In this video, Greenberg presents an overview of the history of human-computer interaction. He also offers up a discussion how an understanding social theory, perception of spatial relationships, and embodied interaction can be applied to the design of natural user interfaces and interactive systems.  Useful examples of interaction design explorations, within an ecological context, are provided later in the video.

Proxemic Interactions: the New Ubicomp?

RELATED

My Backstory

Regular readers of this blog know that to subject interactive displays in public spaces holds my interest. When I was taking computer courses during the mid 2000s, I focused some of my energy on projects designed for large interactive displays, inspired by reading articles like "Physically Large Displays Improve Performance on Spatial Tasks" (Desney S. Tan, Darren Gergle, Peter Scupelli, and Randy Pausch) and "Dynamo: public interactive surface supporting the cooperative sharing and exchange of media" (Shahram Izadi, Harry Brignull, Tom Rodden, Yvonne Rogers, Mia Underwood).  

Jeff Han's 2006 TED talk was another inspiration. I remember my excitement as watched his demonstration of an interactive multi-touch touch screen the size of a drafting board, before the iPhone/iPad was born.  Another inspiration was Hans Rosling's TED Talk  about health statistics, with his animated interactive data visualizations presented on a huge screen.

The following year, I stumbled upon the  NUI-Group while searching for information about multi-touch displays, and was inspired by many of the early members of the group.  I also became acquainted with a world-wide network of people who share similar interests, such as Albrecht Schmidt and his team of researchers at the Unversity of Stuttgart. This busy group recently presented at PerDis 2013 and at CHI 2013 and are involved in a wider range of ongoing projects.

INTERACTIVE DISPLAYS

Alt, F. Sahami, A., Kubitza, T., Schmidt, A.  Interaction Techniques for Creating and Exchanging Content with Public Displays. In: Proceedings of the 2013 ACM Annual Conference on Human Factors in Computing Systems 

Hinrichs, U., Carependale, S., Valkanova, N., Kulkkaniemi, K., Jacucci, G., Moer, A.V., Interactive Public Displays   Computer Graphics, Vol. 33(2) IEEE Computer Society (25-27)

The International Symposium on Pervasive Displays (PerDis 2013)

PerDis 2013 Program
Sample Papers:
Otero, N., Muller, M., Alissandrakis, A., and Milrad, M. Exploring video-based interactions around digital public displays to foster curiosity about science in the schools. PerDis 2013 (pdf)
Alt, F., Schneegass, S., Girgis, M., Schmidt, A. Cognitive Effects of Interactive Public Display Applications. Proceedings of the 2nd ACM International Symposium on Pervasive Displays. 2013
Langeinrich, M., Schmidt, A., Davies, N., and Jose, R.  A practical framework for ethics: the 

Note:  Members of ACM have access to all of the proceedings of PerDis2013 in the ACM Digital Library. Non-members have access to the abstracts.

PD-NET

PD-net approach to supporting ethics compliance in public display studies. Proceedings of the 2nd ACM International Symposium on Pervasive Displays. 139-143
PD-Net 
PD-NET Publications - a great reference list, with links to many papers
Reading List on Pervasive Public Displays
About Instant Places
About the Living Lab for Screens Set

DOOH-DIGITAL OUT-OF-HOME

Digital Out of Home (DOOH): Screens Large and Small at the Mall (and some touch-screen Coke machines!) Interactive Multimedia Technology, 1/1/10

Daily Digital Out of Home post "Billboards That Look Back" : Could miniature cameras embedded in ads lead to Big Brother at the mall? The World Is My Interactive Interface, 5/28/08
J. Müller et al., "Looking Glass: A Field Study on Noticing Interactivity on a Shop Window," Proc. 2012 SIGCHI Conf. Human Factors in Computing Systems (CHI 12), ACM, 2012, pp. 297–306
Michelis, D., Meckel, M. Why Do We Want to Interact With Electronic Billboards in Public Space?  First Workshop on Pervasive Advertising, Pervasive 2009, 5/11/09
The Rage of Interactive Billboards
The Print Innovator, 11/28/12
10 Brilliant Interactive Billboards (Videos)
Amy-Mae Elliot, Mashable, 8/21/11

SOME INTERESTING EARLIER WORK

Jeff Han's 2006 TED Talk (This is worth revisiting, as it came out before the iPhone, iPad, etc.)

Tan, D.S., Gergle, D, Scupelli, P., Pauch, R. Physically large displays improve performance on spatial tasks. ACM Transactions on Computer-Human Interaction, V13(1) 2006 (71-99)

Revisiting promising projects: Dynamo an application for sharing information on large interactive displays in public spaces (blog post)
Lynn Marentette, Interactive Multimedia Technology, 09/16/07

Brignull, H., Izadi, S., Fitzpatrick, G., Rogers, Y., Rodden,  T. The introduction of a shared interactive surface into a communal space. Proceedings of the 2004 ACM conference on Computer supported cooperative work (CSCW'04), Chicago, ACM Press, 2004 (pdf)

Izadi, S., Brignull, H., Rodden, T., Rogers, Y. and Underwood,M. Dynamo: public interactive surface supporting the cooperative sharing and exchange of media. In Proc. User

Interfaces and Software Technologies (UIST’03), Vancouver, ACM Press, 2003, 159-168. (pdf)

Proxemics (Wikipedia)

Why Do We Want to Interact With Electronic Billboards in Public Space? 

WHY DO WE WANT TO INTERACT WITH ELECTRONIC BILLBOARDS IN PUBLIC SPACE? from danielmichelis