I love Foursquare. I'm the reigning Mayor Of The Year, after all, so I've got a lot invested in the system. I've been really impressed with how useful the service has gotten since this summer, so I recorded a few thoughts on the matter which you will now enjoy.
Here's the deals/tip promotion I refer to in the video. Love the integration. Confused by the language. "50% off for free??" Just cut the last two words. You're saying "You don't have to spend money to get 50% off?" Guess what: if I don't spend money, that's actually 100% off for free!