Check this out: Is Your Website a One-Hit Wonder?
Not All Visitors Are Created Equal
As we've touched on in earlier articles in this series, not all visitors who come to your site hold the same value for your business or your bottom line. Perhaps a one-time visitor heard about an article on your site from a friend, and wants to casually peruse (but with no intention of purchasing your product or signing up for your newsletter). On the other hand, perhaps an ad campaign is resonating particularly well with targeted Facebook users — and it's resulting in more high-value traffic and return visitors for your blog.
Read more:
http://mashable.com/2013/12/07/frequency-recency-metrics/
