-By Barry Lowenthal

I was in a client meeting the other day talking about social media and social media monitoring—everyone’s favorite topic these days. This particular client is adept at social media and has close to 2,000,000 fans on Facebook, which even by Facebook standards is a pretty sizeable amount.

The conversation took an interesting turn when we began talking about the resources they were putting against keeping their fan page up to date and how often they should be posting new content and updates. The client who was tasked with overseeing the page noticed that when he posts at a certain frequency more people unfriend the page.  A modern-day churn rate.

I think this is an extraordinary observation, especially as we start to understand how different classic communications metrics, theories and approaches apply (or don’t apply) to the social media world.

A classic offline media metric that’s related to this observation is reach and frequency. It’s a measure of how many people are exposed to a message and how many times they’ll see the message. If frequency is too high, consumers tend to disengage and tune out. If it’s too low, they’re not persuaded to commit to the brand.

Usually the reach and frequency equation is read like this: 92 percent of the target is reached on average 5.6 times and written like this: 92/5.6. In order to maximize efficiencies, media planners spend a lot of time trying to understand how much reach and frequency is too much or too little to persuade a prospect or customer to take a particular action or change an attitude about a product or service. For large advertisers, dropping one reach point can equate to saving millions of dollars.

In the social media space, a new dynamic seems to be developing that directly affects the impact of frequency. It is very related—and very different—from the frequency measure that exists in the offline world. Let’s call that metric the posting rate.

We’re learning very quickly how too much frequency affects the likelihood that we will be able to retain our fans. If we post too often, they will leave because we will become bothersome. This immediacy of response is a real advantage versus the offline world where it takes much longer to measure wear out for TV and radio advertising. Wear out is a direct result of poorly deployed reach and frequency.

Wear out measures how quickly an ad stops working. Eventually, after repeated exposures people just get sick of seeing the same message and tune out. Or, even worse, they develop ill feelings towards the advertiser. Consumers have less and less tolerance for repetition, especially since many advertisers abuse the tactic and incessantly repeat. In social media it appears that consumers have even less tolerance.

But unlike TV wear out—which is not affected by how many people are tuned in to a particular commercial—the social media churn rate is directly affected by how many other posts a Facebook user receives. If someone has a lot of friends (400+) and all the friends are active posters, then a particular post may never be viewed. Usually only about six posts are visible on a 19-inch computer screen, so most posts fall below the fold.

If you don’t check Facebook regularly (every hour or so) and your friends tend to be active posters, you may never see posts older than a few hours. In this case the Facebook user has a greater tolerance for a high posting rate since they only see the most active posters.

In this case, a brand can only combat this by increasing its posting rate to three-plus times per day. If a brand’s fans have large social networks, then posting more than once a day will probably not become annoying.

But if a brand’s fans tend to have smaller social networks (e.g., older Facebook members or retirees), then posting more than once each day will quickly become irritating. In this case, the brand must apply a low posting rate strategy.

Unfortunately, there is no way to limit posts to only people with large social networks. Brands have to experiment to see how many posts are too much. But unlike the dynamic that exists in the offline world, brands can quickly adjust their posting rates to maximize their relationships with their fans and determine their optimal posting rate.

Barry Lowenthal is president of The Media Kitchen, a Kirshenbaum Bond Senecal + Partners company.