After the deal is over (usually the next day) you'll get an email that your voucher is ready to print. It has a unique number on it and the establishment has a list of valid vouchers.

The best ones are when you trade it in and get a gift card, because the gift card will cover taxes, and you can use only part of it and return. Be aware of what the actually voucher is for, many times you'll see a pay $20 for a $45 voucher, only to find typical dinner would cost $30-$35 per person. So unless you go alone, you'll have to spend more.

Both sites, (livingsocial and groupon) appear to have a good return policy, I ordered a meal delivery service once and it was so popular I would have to wait about three months to get the food. I called Groupon and they offered to refund my order.

If you are new to either of them, I would appreciate you using my referral link, for livingsocial using my link will get you a $5 credit after your first purchase.

http://www.groupon.com/r/uu1051168

https://livingsocial.com/redeem_invi...ian-ia?ref=lnk