Facebook pages are becoming more and more popular with marketing your business; today over 800 million users.

Have you ever wondered how much a Facebook fan is worth?

Way back in April 2010 – Virtue, a social marketing group, sought the answer. They came up with a ROI of a Facebook fan is $3.60 annually.

Their research indicates the earned media value of one Facebook fan is $3.60 per year. In addition,

the impression that a single wall post makes on the fan page is 1:1; in other words, for every wall post made public, an impression is made on a fan.

That means one post per day for a month with a fan base of one million would be 60 million impressions.

Virtue placed a $5 CPM (cost per thousand views) value to the earned media. The equation figures that a fan page with one million fans gives $300,000 in earned media a month.

1M impressions x 2 posts x 30 days = 60M impressions

60M impressions / 1000 x $5 CPM = $300,000

Considered in a larger scale, a fan page with one million fans would have the earned media of $3.6 million, annually.

But now that figure has been blown out of the water by Social-media agency SocialCode is the latest firm to try to calculate the value of a Facebook fan as part of a new study. Their verdict: about $10 per “fan,” assuming a constant cost-per-click of $1.

Looking at over 5 million Facebook ads placed by over 50 clients (spanning verticals, but mostly in consumer packaged goods, auto and finance) from between May and September of 2011, the study looked at the cost of acquiring new fans, and what it took to get them to perform a desired action.

It found that fans perform desirable actions such as installing an app, voting in a contest and making a purchase at a much higher rate, and it’s significantly cheaper to prompt them to do so through advertising than it is to prompt non-fans.

The study looked at seven actions a user might perform on a Facebook fan page: app install, contest submission, contest voting, fan acquisition (which encompasses “liking” a sub-brand for existing fans), program sign-up, purchase and sweepstakes. In the aggregated grand total, it found that the difference between the cost per acquisition — calculated by dividing the total cost of clicks by the total number of actions — for fans and non-fans is $9.56.

The total conversion rate for fans, obtained by dividing the total users who performed an action by the total who clicked on an ad, is 19%, compared to 7% for non-fans.

So there you have it, a value of $3.60 in April 2010 and at today’s projected amount the value of a Facebook Fan is $9.56