In the SEO world, the amount of times a website is linked to on the internet, the better for it, but it is the quality of the links along with the number that matters. The most significant difference between bad and good links is the quality of their container or the website they are on.
The quality of a link can be easily checked by checking out the website. The low quality links can be picked up by Google, and the website can be penalised for it.
Link building is part of the backbone of SEO, and bad links are germs that can affect a healthy system; hence they should be gotten rid of as quickly as possible. Usually, websites are not penalised for a few low-quality links, and they can be ignored by the search engine algorithms altogether, but a higher number can be taken as manipulation, which can lead to penalisation.
According to Healthy Links, a link building website, there are five common places that are sources of bad links:
The easiest to pick out is out-of-context links. A disparity between the content on a website and the backlink instantly raises a red flag. A site discussing baby clothes cannot be linked to a site about horse-riding. Context can be picked up by search algorithms, and if an out-of-context link shows up, it is marked as a bad link.
Private Blog network links are also easily picked up as bad links. Since private blog networks can be easily set up to create backlinks to a website, they are low-quality links. Any number of backlinks from PBNs will raise flags. Similarly, social bookmarking is also considered manipulative and classified as low-quality links.
Discussion Forum Links
The quality of links depends on the quality of the website it is gained from, so an established and reputable discussion forum can be a good link source but if the links are manipulative as in repetitive or spammy, then the chances of being penalised are high. Made mostly by Spambots, comments from other websites are also bad links and will stand out. Discussion forums can include sites like Facebook, Reddit etc. but also random sites which do not rank high in the Google Algorithm.
Another type of bad links that stand out are non-local links. For example, if a website is localised to the UK, then comments from other sites out of the UK will be considered bad links. If a business is localised to London, then links from a French website will stand out. If they have relevance to the content, then they probably won’t be picked up on if they are not manipulative.
Any website that provides cheap linking services, of any kinds of links mentioned above is to be avoided. Sites like Fiverr, Upwork, etc., provide dozens of services for link building by PBNs, Guest posting, Spam bots. These are all link paths that should be avoided if you wish to retain the quality of your website.