Article by iClimber.com
There are several types of old Google SEO techniques that no longer work. There used to be manual penalties for Cloaking or sneaky redirects , Unnatural links from your website, Hacked website, Pure spam, and Hidden text or keyword stuffing are just a few. Most of these are these days automatically detected and either penalized or if they are links, the links are not counted. Here are some of the lowest quality types of links that you can acquire which would not help your SEO:
Web directories / Article directories
Abusing web directories and article directories for incoming links is at the top of the list. The only link directories that escape a penalty are manually curated lists. Even then, Google does not penalize sites but chooses to ignore link lists.
Links from International sites are also a problem when they are a majority of the incoming links. Content on foreign language websites that are not relevant contextually raise red flags. Nowadays, the practice is pointless as Google reduced the weighting on links from other languages.
There are hundreds of Coupon codes sites online, and links from them are considered spammy since most of the sites only exist to provide links. There is often no value to the coupons, and there is no content actually to read.
Another issue with affiliate links that are without the no-follow attribute. Google equates that sort of activity with buying links, and the penalty can be severe.
If you have a site that relies heavily on traffic from Google, then make it a regular practice to use online tools to scan and analyze your backlink profile. When you find problematic links, disavow them immediately.