Groupon has wended its way through several of the stages of Kübler-Ross grieving process, finally arriving at acceptance that its Tibet ad just isn't going to fly. The company said yesterday that it would pull the ad, along with the others mocking celebrity-cause campaigns, in response to the overwhelmingly negative reaction after the Tibet spot aired during the Super Bowl. The move is a blow to the startup, which has been on a remarkable hot streak, and calls into question whether Crispin Porter + Bogusky will be next to get the boot. Groupon CEO Andrew Mason was involved in crafting the ads, I was told, and made an interesting statement regarding CP+B in his blog post about the company pulling the spots. "The execution was off," he wrote. He also made clear that Groupon employed "a professional ad agency." It's hard to see how this relationship gets repaired. There's equal responsibility here. Groupon went with CP+B because of its provocative campaigns. It's sowed seeds of controversy plenty of times previously, ranging from Orville Deadenbacher to Whopper Virgins. This was Groupon's first big ad campaign, so it's safe to assume it learned a valuable lesson. I'm told the company doesn't blame CP+B for the fiasco, but at the same time it's still figuring out whether they'll continue working together after what was, to be kind, a rough start.