A few days ago, Foursquare founder Dennis Crowley sent out the mildly amusing Tweet above declaring that he was unsubscribing from Unsubscribe.com , a service that aims to help you clean up your inbox by making it one-click easy to unsubscribe from mailing lists. It works pretty much as advertised. The problem is that it puts you on its own mailing list and periodically sends emails reminding you to use the service. Yeah, that kind of defeats the purpose. Unsubscribe. But what happens when a high profile CEO like Crowley tells his 26,576 Twitter followers that he's had it with your product? Apparently, the world explodes. It's so meta.