Despite the press, geolocation service Foursquare is still pretty small. But it's proven influential in another way: the phenomenon of "checking in" has spread beyond telling people where you are, and a handful of services now focus on letting you "check in" to what you're doing--whether it's attending a concert or reading one of those ubiquitous Stieg Larsson novels.
One of them, GetGlue, announced Wednesday a partnership with HBO to promote its current series "True Blood," "Hung," and "Entourage," in which users who use the GetGlue iPhone app to "check in" and say they're watching those shows can earn insidery "stickers" much like Foursquare's badges. GetGlue focuses on broadcasting which movies or TV shows you're watching, books you're reading, and music you're listening to, and also lets you rate whether you liked the media in question so that you can get personalized recommendations.
GetGlue, which is run by a New York start-up called AdaptiveBlue and already has a handful of deals in place with other media companies, says that it now pulls in 4.5 million unique ratings and check-ins per month. It's a little bit confusing in the way that it attempts to mesh telling your friends what you're watching, reading, or listening to with machine-learning-powered recommendations (I can see a lot of people wanting one or the other, but not both, and was a little bit unnerved at how few permissions GetGlue had in place before automatically publishing my ratings to my Facebook feed) but the company's team said in a phone chat earlier this week that they believe check-ins and recommendations will be growing ever closer.
They're not the only company bringing check-ins beyond geolocation. A mobile app called Hot Potato lets users check in with what they're doing and offered a test promotion with Foursquare at the South by Southwest Interactive Festival this spring to sync up its events listings with Foursquare's venue directory. A fuzzy rumor from earlier this week suggests Facebook may be interested in buying Hot Potato--but for its engineering team, not necessarily the app.
And cable giant Comcast has been testing the waters, too, with a check-in entertainment app called Tunerfish that it rolled out a few months ago.