When trying to establish the value of each Like a brand receives on Facebook, there are several factors to take into account. One of these factors is how many visits to your website each of your fans is worth per year, and Experian Hitwise claims to have created a formula that determines this figure.

Using its data sets, Hitwise has discovered that 1 each new fan on Facebook is equivalent to around additional 20 visits to your website every year. So if you have 5,000 Facebook fans, that equates to around 100,000 website visits over the course of a year.

Hitwise revealed the data as it announced the launch of its new Facebook Fan Acquisition and Analysis service in partnership with social technology company Techlightenment. Hitwise says that:

Our data shows that for the top retailers, even if they have no Facebook fans they can still expect to receive on average 62,000 visits from Facebook each month. However, by utilising this new service, brands can more rapidly build a fan base within Facebook and therefore drive more traffic to their website. Within retail each new fan acquired will drive an additional 20 visits to a retailer’s websites, which in turn will generate extra sales both online and offline.

The figure of 1 fan = 20 extra visits to a website uses a unique methodology that combines Hitwise data with data from Techlightenment. We took the top 100 retailers ranked in the Hitwise Shopping and Classifieds category and benchmarked visits to those websites against the number of fans those brands had on their Facebook page. We then also looked at the propensity for people to search for those retail brands after a visit to Facebook using our Search Sequence tool.

Given that Facebook reportedly now has 750 million monthly active users, that is 13 billion potential extra website visits that are available to brands if they properly harness the power of Facebook. While additional visits from Facebook fans may not necessarily translate into any extra revenue for a brand (unless they operate on an ad-supported revenue model), getting people through the door — or to visit your website in the first place — is an important step in turning a Facebook fan into a customer.

I have one question about this data though: how does the data relate to the 46,808,510 (at the time of this writing) users who Like Facebook?