Facebook has announced the launch of a new tool designed to help marketers understand their conversion rates and optimize their off-Facebook advertisements.

By creating a unique snippet of code and adding it to whatever page they want to monitor (check out pages or registration pages, for example), marketers can now see how many people have clicked or viewed an ad, or taken a desired action. Within this function they can also choose CPM optimized bidding, which, based on standard demographic data and historical click actions, will display adverts to Facebook users most likely to convert.

According to an official Facebook blog post: “This means that marketers who are interested in using Facebook ads and sponsored stories to drive specific actions on their websites can now use conversion measurement to both understand the ROI of their ad spend and to improve that ROI on future campaigns.”

Indeed, the advertisers that have been testing the tool have delivered encouraging results. Online retailer Fab.com, for example, was able to reduce its cost per new customer acquisition by 39%, and the Democratic Governors Association noted a dramatic decrease in its cost per conversion – 85% less than previous campaigns.

However, some have questioned why this tool has only become available now, especially given the hype around Facebook ads that dominated much of 2012 – many marketing teams have their own conversion tracking software in place already.

Facebook worked on a similar function in 2010 but ended beta testing less than a year later, blaming confusion among advertisers and expensive support overheads. According to the company, this offering is different in its efficiency and more straight-forward user interface, with the system doing the bulk of the legwork for the marketer. A comprehensive FAQ on the tool is hoped to smooth over any technical difficulties for those seeking to adopt the tool.