Sessions per User

Sessions per user is the average number of times a user came to the site in a period: total sessions divided by unique users.

This metric is the simplest measure of audience stickiness: a value of one means each user came only once and left, and above one means people return. It is therefore read beside new versus returning to tell whether traffic growth comes from fresh acquisition or from the existing audience coming back. But it has two traps. First, it is an average and the web's skewed distribution hides its shape; a value of one and a half can mean everyone comes roughly twice, or that the majority come once while a loyal minority come twenty times — and the right decision hinges on that minority. Second, it is sensitive to window length: a longer window gives more chance to return so the number naturally rises, and comparison only makes sense across equal-length windows. This metric is the RFM frequency dimension averaged over the whole audience, but as a single figure it says only the overall stickiness, not its structure.