Easy to use administration with basic functions to add, remove, time limits, max amount sold etc referring to coupons.
The ability to add featured coupons from various businesses (published to the front page automatically)
Exact features as groupon and social buddy.
Easy to use and clean front end design.
The ability to share coupon ads on major social networks and blogs
Email to friends and refer to friends.
Easy to use payment system with paypal and major credit cards
mobile site (optional)