I think the "I'm new" excuse can only be used one time. I refer to it as the "one mulligan and you're done" rule. Daily-deal website Groupon (Nasdaq: GRPN) broke that unwritten rule on Friday.

For the second time in less than seven months, Groupon was forced to restate its earnings results. The reasoning this time was that it needed to keep more of its cash in reserve since it has been dealing with higher-priced social deals that could potentially result in larger refunds. The accounting change reduced total fourth-quarter revenue by $14.3 million and widened its already unexpected quarterly loss by an additional $22.6 million, or $0.04 per share. If you recall, Wall Street had actually expected Groupon to earn $0.08 during the quarter.

As I mentioned, this isn't Groupon's first go-around in the restatement department. Before it launched as a publicly traded company last year, the SEC kindly nudged Groupon into changing the way it accounted for revenue. In years past, Groupon would count the full value of the coupon as revenue without accounting for the value its merchants would get. The restatement in September more than halved its 2010 total sales from $713.4 million to $312.9 million. At the time, this restatement also reduced revenue in the first six months of 2011 by nearly 60%.

Not surprisingly, Groupon went through two CFOs last year; both chose to leave after short stints with the company.

How difficult is it to get your accounting facts straight? Not only that, but who releases accounting errors on a Friday evening after the market is closed?

If my suspicions about Groupon's business model weren't fully apparent before, they certainly are now. Back in November, I listed five reasons to avoid Groupon and, I'm proud to say they still hold true today.

The biggest detriment to Groupon's business model is its limited barrier to entry. Anyone with a reasonable amount of cash could create a daily-deal site. At the peak of 2011, 530 daily-deal sites existed, yet it should be noted that 170 of them closed up shop.

You're probably now wondering why so many daily-deal sites were shuttered if the barrier to entry is so small. That's because the cost of acquiring customers in light of the increasing competition is going through the roof. According to The Wall Street Journal, Groupon's cost for acquiring a customer ballooned from $8 in 2010 to $23.50 in 2011. It's no wonder that even with a sizable chunk of the daily-deal market share it can't turn a profit or keep its books in order.

Groupon also isn't getting any help from its larger peers that it should be relying on. Amazon.com (Nasdaq: AMZN) made a $175 million investment in Groupon's rival LivingSocial in late 2010. Google (Nasdaq: GOOG), which was largely expected to acquire Groupon, purchased The Dealmap last year to incorporate local deals into its Google Maps platform and also runs its very own Google Deals daily service. Even Microsoft (Nasdaq: MSFT) is offering a daily-deal service under the name MSN Offers. The money is out there; Groupon just isn't capitalizing on it as many had expected.

The news of more accounting snafus adds more fuel to the fire that Groupon is wandering aimlessly and crossing its fingers in the hope that everything goes as planned. That's not how I invest, and I really, really hope Groupon shareholders are reading the fine print that comes along with owning this bipolar stock.

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