Its not just Groupon anymore in the US market. Groupon has a huge backlog in many business categories in most major cities, so its created a huge market for Groupon clones to thrive and some such as
buywithme.com livingsocial.com weforia.com and
savemore.com are filling in the gap. You've also got clones like
eversave.com and
dealpulp.com that focus more on group deals for websites rather than offline businesses.
I know many local business owners in the Los Angeles area that don't want to wait the 6 months to a year to get their Groupon campaign started so they turn to some of the other major players who now have a huge membership base like Groupon. If you assume each business offers their product or service at a 50% discount, then Groupon takes their 50%, the business is essentially only collecting 25% of their offer. If you factor in non redeemed deals by 20% of the buyers on average, then they are probably looking at closer to a 30-35% return. For many types of businesses with fixed overhead expenses who rely on volume of new customers, these Groupon offerings make perfect sense. Plus they get all of the sales up front even though many of the coupons might not be redeemed for months down the road. For a young startup or a cash strapped business, its perfect.
However, for other businesses who view the Groupon as a "loss leader" or an avenue to brand their service locally, it can be a big mistake that can negatively affect cash flow for months. I've seen some businesses abruptly have to halt their campaign in the middle because they had no idea so many people would buy it so quickly and they didn't want to get caught not being able to fulfill all the new customers. Here's an article about a business who had a negative experience with their Groupon offering
http://www.entrepreneur.com/article/219257
For those of you who view the Groupons as just a bunch of junk offerings, then you haven't been paying attention or live in a small market. Between Groupon and all its clones, I've bought over 50 offerings. Everything from restaurants, massages, trips, contractor services, car washes, oil changes, gym memberships etc..., all things I would have normally bought, but at a 50% + discount.