For consumers, online discount vouchers (like those offered by Groupon.com) have obvious appeal: discounts as large as 90 percent. But for retailers offering the deals through the site, does the publicity compensate for the deep hit to profit margins? This paper sets out to help small businesses decide whether it makes sense to offer discount vouchers
Okay let's take a look at this: The offers are usually for one day only. Most offers still leave room for profit off of the items purchased. You receive new customers which may become regulars. Having exposure is priceless. I do not see any negatives about advertising from that site. You must be responsible and maintain profit margins to keep your overheads in check. If you are able to do that then it is nothing but free publicity.