Another non-scientific anecdote here. I attended a talk with maybe 150 attendees recently and the VC asked the audience who had ever used Foursquare. Then he

Another non-scientific anecdote here. I attended a talk with maybe 150 attendees recently and the VC asked the audience who had ever used Foursquare. Then he asked who had used it in the past month. Almost everyone had tried the product at some point, but very few were still actively using the product.