We have it here in Austin and I've used it a couple of times. Good deals. One email/day, just during weekdays. I think you can probably just bookmark the site if you don't want to get the emails, but I would totally forget. And then I would miss out on 60% off a massage or 50% off some restaurant.
The way it works is there is a special - let's say an hour massage for x% off - at a massage place. You "buy" the groupon through groupon that day for the sales price. Then you get a voucher thing in email to use at the massage place.
Sometimes the deals sell out before I can get one.