New Groupon members can get $10 off their first Groupon purchase of $25 or more. You have to apply promo code WELCOME at checkout. This can only be used once and applies to Local Deals, Goods Deals or Getaways Flash Deals. It is available until the end of year 2016, so no rush.
You can use my referral link to sign up. I would get $10 in Groupon Bucks.