I was recently checking my website for unnecessary 404s, 302s and 301s using ScreamingFrog spider and discovered hundreds of outgoing "dofollow" links to Disqus.com. All with the exact same anchor text:
Disqus is a popular blog-commenting engine that is installed by adding a small JavaScript snippet to a website page and - voilĂ - the page has a comments section now. But where did all these links come from?
Here's what's happened - Disqus' installation snippet comes with a link, that most people don't notice and/or forget to remove:
There's actually two "powered by" links, one inside the <noscript>
section, one outside. Those links have nothing to do with the functionality, removing them changes absolutely nothing.
On a side note, I personally believe there's nothing wrong with adding a "powered by" bottom link to your software, preferably, a "nofollowed" one (we were actually doing it ourselves in the past and got slapped by Google Penguin really hard but that's a different story). Also, Disqus makes a fine product and I don't mind linking to good stuff... But.
But the link is just one side of the coin.
Except for this is not exactly a "powered by" link, since its being shown to search engines only. Actual users do not see the link. Disqus' JavaScript removes this link during the page render. It's not present in the DOM if you look at the "developer tools" in a browser:
I have actually looked at their JavaScript and discovered the removing code:
So the real question is: why bother placing a "powered by" link just to hide it later via JavaScript?
The answer is simple: For Googlebot
This kinda looks like "cloaking" to me but let's just hope they made a mistake. Anyways, don't forget to remove that link when installing the code. Otherwise you're just another page linking to Disqus without even knowing it. Out of a whooping 240 MILLION PAGES: