IF I DIE is a unique Facebook app that enables people to leave a message that will leave a message that will only be published after they die. To get the word out on this unique service (since nobody thinks they will die anytime soon), the agency involved used APIs from popular location based services such as Foursquare and combined with Twitter searches for "Facebook Places" to track thousands of check-ins worldwide. With this information, they knew where someone was in real time and could communicate the message to the person in context to his/her location (the message being "Death can catch you anywhere, anytime, even at [Your current location]). A morbid but interesting execution which I think can be used in spirit for some pretty interesting brand campaigns leveraging on people's real time locations.
Sources: Google is buying Lytro for about $40M
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