I’ve done a bunch of social media panels, and a favorite query at these events goes something like this: “How much is a Facebook fan worth?” Depending on which study you read, you’ll see estimates ranging from a few dollars each to $120 dollars a head. And I always tell people, if the answer is anywhere near that $120 figure, I need to ask for a raise.

A large raise.

I can’t give you a figure that tells me what each of the Boston Celtics’ 5.5 million Facebook fans is worth, and honestly, if you’re trying to write an algorithm that will answer the question, you’re wasting your time.

Becoming a Facebook fan takes one click of the button. It’s not a commitment of time, energy or money. Not all Facebook fans are created equally. Some will complain you don’t post enough. Others will unlike you once you start bombarding their News Feed with updates. And most will never even see your brilliant status updates thanks to Edge Rank, the formula Facebook uses to determine exactly what makes it to your News Feed in the first place.

Multiple studies suggest that most Facebook fans never return to your Fan Page after they’ve “Liked” your brand. I’d argue many of them probably never even made it to your page at all. According to our Facebook Insights data, last month, only 13 percent of our new Facebook fans liked the Celtics from our Fan Page or a shared News Feed update. Seventy-three percent liked us from their own profile (organically, while filling out their interests) or saw our logo on a friend’s profile and hit “Like” there.

The point is, your fans are coming in from many different angles. But profiles tend to be the leading source of “Likes”, so who likes you already has a large impact on who will to decide to “Like” you today and tomorrow. So a Like from a celebrity’s page or another brand itself is probably far more valuable than one from Joe Schmo.

So what’s the true value of a Facebook fan? Here’s a better question: What’s the lifetime value of a fan in your marketing database? How much will they spend on your products? You probably already have a metric for those database questions, and frankly, I think those are far more informative and important ROI metrics.

Still, since Facebook is the newest toy on the shelf, brands and their CMOs are more focused counting “Likes”, because it’s an easy comparative metric. But digital marketers should really be focusing their energy on collecting demographic data from their Facebook fan base, regardless of its size.

What data can you glean? Insights is a good start if you haven’t already looked, but it only tells part of the story. If you want some quick feedback, try posting a Facebook question to your fan base. If you want a more robust dataset, set up a Survey Monkey account, give your fans an incentive to fill out the form, and compose a survey they can complete in 5-10 minutes.

If you need still more data, you can go through the process of buying a Facebook ad, and start targeting your potential ad with various parameters, and Facebook will give you a real-time estimate of how many fans you reach. Make sure you’re sorting by fans who are already fans of your brand. You don’t have to actually buy that ad, but the targeting process is a quick and dirty way to figure out things like where your Facebook fans live, or get a percentage of their marital status. It’s not exact, and it’s a little clunky, but with a bit of digging you can unearth some advanced metrics that Insights doesn’t currently provide.

Finally, there are a few vendors out there who are working on aggregating data from multiple fan pages, and may be able to help you get a better picture of your overall Facebook audience.

Rather than worrying about the size of your fan page, or the value of a Facebook fan, why not spend some time learning about that fan base instead? In digital marketing, a little data goes a long way.

This piece originally appeared as a guest blog for the Social Media Club on November 4, 2011.