Not every link helps. Some are neutral, some get in the way. Telling them apart keeps you from buying the wrong service — and most bad links arrive precisely by purchase.
How to recognise them
A link is suspect when:
- it comes from a site with no relation to your subject;
- it sits on a page full of links to businesses with nothing to do with each other;
- the site seems to exist only to host links;
- the surrounding content is automated text, meaningless or oddly translated;
- hundreds appeared at once, without you doing anything.
Where they usually come from
Almost always from three places: cheap link packages, tools that submit your site in bulk, and networks of sites built to sell rankings. All of them promise fast and cheap results.
There is also the involuntary case: sites that copy someone else’s content and carry the links along.
What to do
First, stop producing them. Cancelling the service that is generating those links solves most cases, because ignored links do no active damage.
If there is real volume and a clear sign of trouble — a sharp drop in position with no other explanation — Google offers the link disavow tool in Search Console. It is a blunt instrument and should be the last resort, not the first.
The best cure is not needing one
Links earned from places that have something to do with what you do never raise this question. It is slower, and it is the only route that does not have to be undone later.