I was looking for a deal for a specific service today and my first thought was to go to a group buying site to see what was available. Sure enough, I found a lot of different companies offering the service that was needed except they were all priced differently. The tricky thing with these sites is that you usually enter in with the mentality that cheaper is better and that the the discount they are offering must be as big as they say it is.
With that in mind I always think that if you ever buy things from these kinds of sites you have to do the extra due diligence to see how credible/reputable the business actually is. Too many horror stories out there where people get these items for example only to learn that the discount is over exaggerated or that the company is not as cracked up as it advertises itself to be. I think the only real stuff that you can be super confident about without too much research is if it is an official company offering things like a giftcard for a discounted price. That actually does happen a lot too. Hopefully I scrutinized this offer enough though as $100 savings seems good to me.