Foursquare's 15m users have checked in 1.5bn times

"Crowley said the 15 million global Foursquare users have checked in 1.5 billion times. With such a critical mass of data, the company is developing the ability to become the Amazon of locations: Serving up recommendations for places you would probably like to visit based on your profile and check-in history."

Source:  CNN Money, 29th February 2012

The top 10 shows on GetGlue had 10m checkins in 2011

"Today we're presenting full-year 2011 top 10 check-in data that the GetGlue team pulled together for us, revealing more than 6 million total check-ins for shows from "The Big Bang Theory" to "The Walking Dead." [...]
CBS's "The Big Bang Theory" dominated our weekly charts for much of the fall -- right from its two-episode season premiere, when it grabbed the No. 1 check-in spot in and topped the Nielsen ratings for its night (taking the No. 1 and No. 2 spots with its back-to-back fresh episodes). Throughout the fall it also got a big check-in boost thanks to being in syndication. No surprise that it takes the top spot in our full-year 2011 chart, with nearly 1.1 million check-ins.
Only two comedies -- "Big Bang Theory" and Fox's "Glee" -- land in our Top 10, unless you count the accidentally hilarious "American Horror Story" on FX.
No reality TV made the Top 10. How nice!
"There's not one drama here without a sci-fi or supernatural aspect to it," GetGlue CEO Alex Iskold points out. "And 'American Horror Story,' the only new show for 2011 to make the Top 10, is full of paranormal intrigue.""

Source:  Data from GetGlue reported in AdAge, 4th January 2012

Follow the link to see the full top 10

The three new-for-fall US TV shows with the highest number of GetGlue checkins got recommissioned

"Good news for three out of three of the new-this-fall shows that did make our cut: Fox's "New Girl" and FX's "American Horror Story" have been officially renewed by their networks, and "Once Upon a Time" has gotten a renewal of sorts too -- a full-season order from ABC that bodes well for a full second season. As I've noted before, social-TV popularity and Nielsen ratings are likely to never have an exactly linear correlation, but it's becoming more and more obvious that the shows social-media users are most passionate about have pretty good odds of not only surviving but becoming part of the pop-cultural conversation."

Source:  Analysis of GetGlue checkins in AdAge, 15th November 2011

Note - as it says, there's no direct linear relationship between checkins (or buzz) & viewing, but the shows that people make an effort to check in for are likely to be the ones that people enjoy most or feel most passionate about.