I don’t generally use coupons, but I think Groupon is brilliant in its simplicity.  When you arrive at the site, there’s really only one question.

Here’s a great quote from Andrew Mason, founder of Groupon (from ChicagoMag.com):

The premise is “dead-simple value that you can comprehend by looking at one page in three seconds,” says Mason.

In the age of TMI (too much information), this concept will make or break a business.