Kim Kardashian, Justin Bieber and other celebrities saw their Instagram accounts lose more than a million followers each as the mobile photo and video sharing site continued its purge of bogus accounts.

Kim Kardashian lost 1.3 million of her 23 million followers while Bieber lost more than 3.5 million of his 23 million followers in the assault on spammy accounts, according to recent statistics from Web developer Zach Allia. The changes underscore how spam remains a major issue for social media sites, raising implications for marketers eyeing investment based on following numbers.

?A lot of stars do buy fake followers to pad their follow numbers and? many just attract fake spam accounts that try to piggyback on their fame,? said Ken Wisnesfki, CEO and founder of WebiMax. ??Companies and brands will cozy up to celebs and pay big bucks to get them? to broadcast a message.??

?The fact is that a high number of followers, fake or not, does have the ?effect of attracting a percentage of real followers,? he said. ?So buying fake ?followers wasn't or still isn't necessarily a bad investment, when you?consider the amount of money stars get paid to broadcast a message from? other brands.? ??

In April, Facebook-owned Instagram began purging old, inactive and spam-ridden accounts, its first across-the-board cleanout.

The site?s objective was to provide a more authentic experience and genuinely reflect users who were actually engaging with content.

Instagram warned users at the time that they could see a drop in followers, as the purge continued.

Among other major casualties, Katy Perry lost 2.9 million of her 11.1 million followers. Beyoncé lost more than 800,000 of her 22 million followers. 

The cost of the purge to a celebrity?s name-brand value is real in dollar terms.

?At the intersection of celebrity and social media lies an advertising opportunity for brands, who will pay big money for a star to mention their product or brand,? Mr. Wisnefski said.

 

?Since social media is essentially a broadcasting tool, a larger following should equal higher visibility. That number turns out to be not what it is cracked up to be,? he said.

In addition to the problem posed by companies inflating a person's following number with fake profiles so they look more popular, the problem is further compounded by marketers basing investments on the fake accounts.

Instagram is using an algorithm designed to root out and destroy these accounts, because they are providing no value to either real users of Instagram, or Instagram itself.

Moreover, managing all those fake accounts costs Instagram money.  

?Instagram's own value is in their number of actual users looking for actual content from their friends, celebrities, other people of interest, and, yes, even brands,? Mr. Wisnefski said.   

 

?Creating fake accounts is basically gaming Instagram's system in hopes of generating more revenue for the ones financing their creation,? he said. ?It provides no revenue to Instagram, who is out pitching their own ad products, and gets to make the rules.?

The practice of creating fake accounts can have the effect of annoying actual users, and gives other social media networks an opening to claim they operate without spam accounts.

 

Instagram's purge of bogus accounts is similar to Google?s. 

Google has a vested monetary interest in remaining the number one search engine, so it constantly tweaks its algorithm to root out practices that it deems valueless or spam-ridden to actual people searching for actual valuable content. 

 

??Brands should absolutely stop paying a celebrity so much if their follow/friend/fan number deflates, proportional to the deflation of course,? Mr. Wisnefski said. 

?In that regard this can be very costly. Social media and specifically Instagram is very much a mobile phenomenon, as there are only so many interesting pictures you can take sitting at your desktop computer.?

The Instagram purge may mark a turning point in strategy for marketers who were leaning on fake followers too heavily on Instagram, although predicting the brand-image cost to celebrities is difficult to predict.

?Kim Kardashian has 27 million followers on Twitter,? Mr. Wisnefski said. ?But the network that made her a household name, E!, only has 7 million.?