greenpulse reports several different reach statistics, especially on the media details page:

A short explanation of these numbers:

Monthly visits: the total amount of visits in the last month, as reported by Similarweb;
Unique visitors: the total amount of unique visitors in the last month, as reported by Similarweb;
Article reach: our best estimate for the reach of a single published article for this media.

We calculate article reach with the following formula:
monthly visits / pages per visit * correction factor = article reach
…where the correction factor is 0,1 for high-relevance media, 0,05 for medium-relevance media, and 0,01 for low-relevance media.

Correction factors can be applied per Similarweb top-level category. A correction factor of 0,05 means we expect an article to be read by 5% (1 out of 20) of the visitors.