I want to know how drupal.org counts the websites which use a specified module, as example in views module page reports:
Reported installs: 717,794 sites currently report using this module. View usage statistics.
It is not hard to find the number of downloads but I want to know how drupal.org gets
Is there any way to find out the number of websites that use my custom modules that are not published in the drupal.org website?