Data from Google Analytics (see below for October 2019) shows that the corpora from English-Corpora.org are used by about 120,000 unique people  each month (i.e. if a person uses one corpus 10 times in a month, another corpus 6 times, and a third corpus 4 times, that would count as just "one" person). We are not aware of any other corpus site that has even half as many users as English-Corpora.org.

The users come from all over the world. For example, the following table shows the countries that had the most distinct users during from Apr-Oct 2019. You can also find those from different countries who have registered as "researchers".