Facebook released a new ad metric this week that rates the relevance of ads on a 1 to 10 scale after 500 impressions. Facebook released this new metric to benefit advertisers in three areas: lowering costs, testing creative, and optimizing campaigns already in progress. This metric is valuable as one of the marketer’s most useful tools for gauging relevance of Facebook ads is cost per thousand impressions. A low score means that the intended audience or the ad’s creative needs to be refreshed. - Link