How do we calculate it?
We use large, statistically significant sample subsets from our users for a given variable, which allow us to generate an accurate distribution curve and quantiles based on that real data. This allows you to be confident of the benchmark distribution, and where you fall upon it.
What are they?
The benchmark distribution represents the proportions of a population given some variable. For example, Facebook “Fans” could be a variable, and the benchmark distribution would show you where everyone falls in terms of the number of “Fans” they have received.