Checking the next service to find paid links, I decided to try it on the main page of
exler.ru . Service reported about 5 links. I was surprised the first time. Opened the main and, indeed, in the footer of the page you can see two blocks. The form and content are very similar to the exchange-reference:

Surprised more. Well, it turns out? The 62nd blog in the Yandex rating, with a attendance of 35 thousand people a day, and in general a “well-known network writer” considers the earning methods that are contrary to the TOC of search engines acceptable.
Seeming to blame the crisis. No other way.
Ps. Interestingly, I did not find any contextual advertising from Google or Yandex on the site. Although it used to be.