Mitch Lipka, dealnews Consumer Advocate With the emergence of Groupon, Living Social and the myriad of other local sites offering discounts, deals abound and people are snapping them up constantly. But what do you do if you get a little overzealous in your buying? You get stuck with coupons for deals that you won't end up using. An estimated one in five deal vouchers go unused, and that's a lot of cash being wasted. Enter sites like Lifesta, CoupRecoup and DealsGoRound, which offer a secondary market and a chance for consumers to recoup some cash whether from buyer's remorse, or if the terms of the deal don't fit their schedules. "The need for a marketplace that allows people to sell the deals they won't use is obvious," says Yael Gavish, co-founder and CEO of Lifesta. And there's then a secondary deal market for those seeking extra bargains — if you're really into local deals you can just troll the reselling market for used deals you didn't get the first time around. Some of the Groupon and Living Social deals are offered at a fraction of the original offering so the purchaser can avoid experiencing a total loss. Many sellers, though, are looking to get the full coupon value. But no matter the price, there is another benefit for bargain hunters: You can pick up a deal after it has stopped being offered. Reselling sites seem to be faring pretty well with consumers and, even though they are relatively new, initial indicators show that they're not generating a lot of complaints. And though the sites' missions are similar, they don't work the same. Lifesta, which has risen to the top of the heap, works much like eBay's buy-it-now concept and uses Amazon.com's payment system to process transactions. Sellers, who get reptuation-based ratings, pay a fee for listings and a percentage of the sales to the site. DealsGoRound also takes a percentage of the sale of the deal, and uses PayPal for transactions. CoupRecoup is more like a classified ad site, like Craigslist, but with a focus on only one category. It directs users to PayPal but doesn't take a fee. Both DealsGoRound and Lifesta have "guarantees" of some form. DealsGoRound has a fraud prevention guarantee while Lifesta's policy appears to go a bit further by also backing the validity of the vouchers. CoupRecoup doesn't have something similar because of the way it is set up. "Its model is best described as 'Craigslistesque,'" says co-founder Aren Sandersen. "We are strictly acting as a marketplace, helping buyers and sellers find each other. We don't charge commissions to the buyer or the seller and we don't facilitate the payment. Since we derive no revenue from the site, we don't offer any guarantees or protections." But CoupRecoup and the others all say they will act against any seller trying to move fraudulent deals. Here are two important things to keep in mind when buying from these reseller sites: 1) Pay close attention to the expiration date of the deal. Some might have just a short period left. 2) If you have a problem with a transaction, immediately contact the site — because they're just ramping up business, they tend to be quite responsive. If you don't get attention promptly and have the situation rectified, contact your credit card company to dispute the charge. Mitch Lipka is an investigative journalist for consumer issues who formerly wrote for WalletPop.com, Consumer Reports, the Philadelphia Inquirer and the Fort Lauderdale Sun-Sentinel,among other places. Follow him on Twitter — @mitchlipka or on Facebook. You can also sign up for an e-mail alert for all dealnews features.