Using a service without paying? If you're not the customer, you're the product...

Don't Be A Free User:

"Were you a big Gowalla fan? Did you like Dodgeball? Did you think Trunk.ly (gasp!) was better than Pinboard? Did you make a lot of contributions to Nextstop? Do you miss Aardvark and EtherPad? Did "I Want Sandy" change your life?

These projects are all very different, but the dynamic is the same. Someone builds a cool, free product, it gets popular, and that popularity attracts a buyer. The new owner shuts the product down and the founders issue a glowing press release about how excited they are about synergies going forward. They are never heard from again."