Most of those people are idiots. Even if you don't take into account everything listed in that post, considering you need enough people to tip a deal for it to work is hard enough. In the early stages of building a Groupon clone, the toughest challenge is getting enough people on board day 1 to tip a deal. If you don't get enough people and the deal doesn't tip, you already suck. Most people who aren't in the marketing world don't realize how difficult this is and I'm sure this is at the top of the list for many of the 2000+ Groupon clones as to why they fail. The ones that succeed are those lucky enough to get enough users early on to tip onto the next stage. But even then there are more challenges than merely how "simple" an idea Groupon is. And Groupon isn't the only exception. Every startup has a list of challenges people on the outside can only begin to imagine.