The homepages of the biggest online poker room in the world, PokerStars (pokerstars.com & pokerstars.net), disappered off the face of Google earlier this week. The poker blogosphere was ablaze with suggestion as to the cause. Some suggest it was caused by Google penalizing the website for some violation of its rules, such as pay links. Some even go so far as to suggest it was caused by some new crackdown of online poker by the government.
The truth were none of that, though equally exciting. It turns out some enterprising employee had decided to add "noindex, nofollow" tag to its .net homepage, while changing server settings for its .com website so that its (many) affiliate URLs were no longer returning a 301 but as a normal page of its own. Guess what happened when Google automatically selected a canonical URL that wasn't its homepage but one of its affiliate link, and one that doesn't rank very highly?