In addition to being perfectly content to watch reruns of my favorite TV shows (I’m looking at you, Big Bang Theory on TBS), I also can watch my favorite TV commercials again and again. For example, I love AT&T’s “Bedazzling” spot.  I laugh out loud every time I see it, which is often because it airs frequently while I’m watching Big Bang Theory reruns.

As happy as I am to watch this ad again and again, on Facebook (or YouTube, for that matter) the experience is strangely different. If you visit the link above, you’ll see that this video has been seen by about 26,000 people, which represents a tiny fraction of those who have seen it on television. If it’s such a hit on TV, why hasn’t that popularity carried over to digital video?

The answer explains one of the top causes of Facebook campaign death: ad creative fatigue.

My theory here is that advertising popularity hinges on the medium itself. Television viewers have been conditioned to accept the linear and relatively limited nature of the medium. We watch what networks curate and publish for us, and we accept that even with a remote control in hand, the number of desirable alternatives at any given time is limited by the hour we’re tuned in and the networks we’re willing to watch.

If you believe as I do that there is a reasonable chance of seeing a favorite TV ad during a commercial break, it reduces your incentive to change the channel. The expected utility of either option is so even in many instances that it’s just not worth picking up the remote.

On Facebook, it’s quite different. My perceived options are nearly limitless. That means I’m much more inclined to believe that I can find something new I’d rather watch, read, or play than a commercial I’ve seen even just once before.

In other words, ads on Facebook tend to get old much faster than on television.

Fortunately, marketers can do something to prevent ad fatigue: they can proactively plan to change the creative before fatigue sets in.

Facebook makes it very easy to determine actual reach and frequency, so marketers can know how many of their target audience has seen an ad. After being seen anywhere between three and five times, it’s probably a good idea to retire an ad and replace it with something else, ideally something that continues whatever narrative the retiring ad may have started.

Running a series of videos can be too expensive for even the biggest marketing spenders, but don’t let that deter you. For example, AT&T could start with its “Bedazzling” video spot, and then follow it with static imagery showing the sheepish sales associate’s bedazzling projects, or with a cinemagraph that shows her bedazzled shirt sparkling away.

The best marketers on Facebook know that unlike on TV, ads on Facebook have a remarkably short shelf life. They also know that once a campaign has started to decline, it can be really difficult to recapture its momentum. That’s why they have developed a shot clock in their heads that tells them when it’s time to proactively change even popular and top performing creative.

If you’re preparing to launch a campaign on Facebook, make sure you’ve got enough ad variety to prevent your campaign from suffering ad fatigue.