The competition for most outlandish criticism of Groupon is getting really boring. All of these articles ignore the same basic facts.
Groupon is spending a huge amount on customer acquisition. They've stated numerous times that this is a short-term competitive play, to try to create as much of an advantage as possible to counteract the dozens of clones by building up their brand awareness and subscriber list. The idea that they are a ponzi scheme or the next Madoff because they are choosing a fast-growth strategy is absurd. I might disagree that this is a smarter strategy than growing more slowly, but this doesn't prove that they're insolvent or something. Existing customers don't stop spending after one purchase, so the idea that they have to spend on acquisition in order to make money to cover operating costs is nonsense. They have total control over how much they spend on customer acquisition, and at a certain point will have to slow down. Again, you can disagree with their strategy, but there's no scam here.
Likewise, there is no evidence that any majority of businesses who work with Groupon, or customers who purchase Groupons, are overwhelmingly dissatisfied with the value they get. Tons of business still agree to run groupons every day, including businesses that have run groupons many times. Obviously, it's not a great experience for everyone, and I'm not even arguing that in the long term this model will do well. But to say that Groupon doesn't do anything or provides no value just isn't backed up by any credible evidence, at least that's been present in all these threads.
Boston is not Groupon's oldest or largest market. And the numbers in that article are to be expected, and aren't really "troubling" as the BI article's source states. Groupon is spending money to acquire more subscribers because the initial trove of low-hanging fruit has already been acquired. They're trying to keep a big market from rival companies, so they're going after people who are more difficult to acquire (and obviously therefor less likely to spend). Anyone who expects these more difficult acquisitions to spend the same amount per user as people who found their way to Groupon more easily is ridiculous.
I'm not arguing that Groupon isn't overvalued, or that their model doesn't have problems. But the arguments that Groupon is a scam or not a real business or that they're going to have to close up shop any day now range from unsophisticated to dishonest.