As part of its ongoing quest for transparency, Facebook this week began deleting thousands of fake user accounts and illegitimate likes from its network. The exact number of purged accounts remains unclear, though many pages saw a substantial decrease in fans over the course of a single day.

According to PageData, a Facebook metrics service, Zynga's Texas HoldEm Poker page lost more than 96,000 likes on Wednesday alone, while fan pages for Lady Gaga and Rihanna saw similarly steep drops (31,700 and 22,000, respectively). Also taking a hit were pages for FarmVille, which lost more than 45,000 likes, and Justin Bieber, whose Facebook fan base declined by nearly 18,000.

The purge is underway

Wednesday's purge comes nearly a month after Facebook announced plans to crack down on zombie accounts and likes, as part of an effort to guarantee authenticity across the site. "These newly improved automated efforts will remove those Likes gained by malware, compromised accounts, deceived users, or purchased bulk Likes," the company wrote in a blog post last month. "While we have always had dedicated protections against each of these threats on Facebook, these improved systems have been specifically configured to identify and take action against suspicious Likes."

Facebook also said the impact on fan bases should be minimal, estimating an average decline of less than one percent. Thus far, that's rung true; Texas HoldEm Poker's loss, while large in absolute terms, comprised just 0.15 percent of its roughly 63 million fans. And while some businesses may cringe at the thought of losing so many fans in a single day, a more transparent fan base will ultimately result in more realistic metrics, while helping to deter spammers, as well.