from wikipedia:

Red Lobster has offered an endless snow crab leg promotion twice in its history (as of September 2003). However, in 2003, the promotion resulted in its parent company, Darden Restaurants, taking a $3 million charge to third-quarter earnings, resulting in president Edna Morris's departure from the company.

The chain also underestimated how many times a customer would order more. Further complicating matters at the restaurant level was the time customers spent table-side in the restaurant cracking crab legs. This resulted in increased waiting times in the lobby and overall diminished customer capacity per hour.