I know my check-ins have dramatically declined in the past 6 months. I might check in once or twice a week just to see who is nearby.
The news is worse for Facebook Places and Yelp (who already had huge user bases before implement check-in services). See this chart from Business Insider.
I’m not sure I can put my finger on the reason for this backslide. Did the game of collecting badges grow weary on users? Are the likes of Foursquare and Gowalla geared towards early-adapters? Has the value of checking-in declined?