This evening I went to Münster to meet with Antonio Krüger and Lucia Terrenghi (who is now with Vodafone), who was visiting there. Advertisement is a hot topic and it was interesting that we shared an interesting observation “If the advert/information is the least boring thing to look at people will read it ;-)”. Each of us having their favorite anecdotal evidence: my favorites are people reading the same map everyday at their U-station and the advertising flyers in the Munich S-Train. For context-aware advertisement this is the major challenge to find the time/location where people are bored and happy to see an advert 😉
Looking for some more on the topic I realized that Google Patent search works quite well by now: http://www.google.de/patents
[1] Vert, Inc. http://www.vert.net/patented.html
[2] Hacking Taxi Cab Billboards. http://www.theshiftedlibrarian.com/2002/07/31.html#a2715