Someone asked me about adult spam links and whether or not they should disavow them. There are two sides to whether they should disavow.
Many sites collect adult links naturally, like barnacles on a ship. They eventually drop off and are replaced by other spam links and that likewise disappear in time.
This usually happens when a site begins to rank well. The better a site ranks the more attention from spammers and hackers the site will attract.
Why Do Spammers Link with Spam Links?
I believe it happens because there is a belief that linking to authoritative sites will help a site avoid being caught by Google. This belief stems from an old algorithm related to Hubs and Authorities.
The concept of hubs and authorities, though originated in the 1990’s, still persists in the old SEO advice that you should link to “authority” sites from your content because it’ll help you rank better.
Of course, that practice is no longer correct and probably never was. Look at any top ranked site for any keyword phrase in any niche and you’ll likely see that it’s not linking to an “authority” site.
For further reading, check out the Link Analysis section of HTML version of a book called Introduction to Information Retrieval. It discusses PageRank and Hubs and Authorities.
Do Spam Links Hurt a Site?
Spam links point to quality sites. Quality sites don’t point to spam sites. So when the link graph is calculated, visualize it in terms of space and the galaxies in different parts of the universe. Each galaxy contains planetary systems and so on. And all those galaxies exist in large clusters of galaxies.
Spam sites tend to isolate themselves way apart from the clusters of normal sites. There are no meaningful connections from the normal sites to the spam sites.
So regardless how much they link out to quality sites, they still cannot become a part of the normal constellation of websites.
So they’re easy to spot and remove from what’s called the Reduced Link Graph. That’s probably how they’re not counted for link ranking and why they don’t affect the rankings of a normal site.
Should You Disavow Spam Links?
If it makes you feel better there’s no harm in uploading a disavow file.
If you want to test the effect of uploading a disavow, to see if it makes a difference then do a test. Make no changes to the site before and after uploading the disavow file. If there’s an immediate change in rankings then maybe it had an effect. But I suspect there will not be a change.
Links and Rankings
It seems to me that content is the big deciding factor for rankings and that increasingly, links play a validating role (“this site is legit” ).
As for anchor text, based on my experience, anchor text is used less. Why it’s used less is an open question. Is it used less because the link is judged to not be editorially given? That could be.
It could also be that the text around the link, the context of the link, may play a role similar to what anchor text used to play.
What is Google’s Advice on Disavow Tool?
Googlers have been on record for years and years, dating back to the creation of the tool that publishers don’t really need to use it. The only time they should use it is when they know the links are paid for or not trustworthy because the publisher is responsible for them.
I know it seems like Google has issued contradictory advice, but if you see any article that shows a Googler encouraging people to use the disavow, go watch the Webmaster Hangout that the article might be based on and see what the context of that statement is. Many times a partial context is used in order to make it seem like John Mueller is recommending it when in fact he is not.
That’s why I wrote an article featuring a full transcript of a recent Webmaster Hangout where Mueller is clearly reluctant to recommend the use of the disavow tool. Read it, watch the video and judge for yourself.
So it’s up to you. If disavowing adult links reduces your anxiety then go ahead and do it. But consider being scientific about it and monitor the results.
If nothing changes you can have more confidence that ignoring those links won’t harm you. If rankings improve, then… bonus!