You’ve no doubt seen something like this happen: a group tries to initiate a public relations campaign online to try to improve their popularity, only to have it tremendously backfire. Just in the past few weeks, we’ve seen Bill Cosby try to meme himself, 19 Kids and Counting counter-petition themselves to stay on the air, and Kirk Cameron try to improve his latest movie’s rating on Rotten Tomatoes. All of which wound up colossal failures. Cosby saw his image accompanying snide commentary about his alleged rapings, the Duggars found their Twitter hastag taken over with unbridled sarcasm, and Cameron was intellectually flayed.

All of these incidents boil down to the same problem: they were all trying use their existing fans to bolster their public image without realizing that they all had significant numbers of detractors who were more interested in seeing them brought down.

There are a number of ways to improve someone’s image. And, prior to the internet, all of those ways were essentially one-way communications. Advertising, public appearances (often controlled), “suggested” stories run in media outlets… That all makes sense, and how much is done here usually is controlled by how much someone’s willing to spend. With the internet, however, people see this as a great opportunity because it’s dirt cheap compared to other outlets, and has a much broader reach. Furthermore, the very nature of the two-way communications means that fans are able to help boost the signal into regions that might not be functionally accessible otherwise. Often, they’ll even be happy to do this for free.

What people don’t always realize, though, is that the two-way communication means that this can only be effective for a subset of people wanting to improve their image. Namely, those who don’t have an image in the first place. For those who are already known entities, and find themselves fighting a PR battle to restore a tarnished image, fans will not be able to help. Because for as easy as it is for fans to promote someone or something, it’s just as easy for the aggrivated parties to do the same.

The only way this can end in a net positive for the Cosbys, Duggars and Camerons out there is if their fans are so dedicated, so loyal, and so committed to helping that they can out-weight the loudest and fiercest opponents. Which, if you’ve spent any time online, you’ll know is quite rare. The mere fact that they’re trying to deal with a PR problem in the first place suggests that they’ve got a vociferous group advocating against them already. One might understand in a case like Cosby, where he spent literally decades as a wholesome, well-loved, family comedian, how he might be blind to the growing sentiment against him. While he hasn’t been idle or completely out of the limelight since The Cosby Show went off the air in 1992, he hasn’t been exactly central to comedy or popular culture either. There’s an entire generation now that may have caught some of his shows in re-runs, but are only interested in the same way they might be interested in My Three Sons or The Adventures of Ozzie and Harriet.

With that kind of remove, you can’t count on fans being as devoted as they might’ve once been. The immediacy with which they may have enjoyed work when it first appeared diminishes with time. And while it may continue to be enjoyed, it becomes more nostalgic than fresh and energizing. And while a good many people do enjoy nostalgia, they’re not as prone to fight for it as who and what is speaking to them right now.

Social media is still new enough and changing quickly enough that it’s difficult to get a good grasp on how it best works. But trying to improve a faltering public image by engaging in fans online is almost certainly doomed to mockery and an increasingly worsening image at best. Admittedly, it’s not always easy to get a good read on how many and how devoted someone’s fans are, but if there’s a group of anti-fans out there, it’s probably a safe bet that you don’t have nearly enough of a positive fanbase to start your own “viral” campaign.