Link building goes together with any online marketing campaigns. It is not surprising that web owners would try anything and everything to increase the number of their links. While it is understandable for you to want as much links as possible, there is a thin line between ethical linking strategy and spamming. No one likes spam. If users dislike it, you can be sure that Google absolutely hates it. For this reason, the search engine has strict safeguards that are put in place to ensure that web owners would comply with its rules. We’ll outline some of the common strategies that are penalised:

Anchor Text Overuse

Going overboard with one anchor text may trigger Google penalty. So there might be a dilemma. Using anchor texts are highly effective if the links come from organic sources. It becomes a problem when it becomes obvious that you are getting links from inorganic sources with anchor texts that are completely similar. For example, if you are targeting the term “auto insurance”, it looks suspicious if everyone is linking back to your site using “auto insurance”.
Varying the way these anchor texts appear may provide some level of protection. For example, by making simple modifications like “Auto Insurance” and “Auto insurance”, it will appeal a bit more natural. Some marketers prefer to vary the target term such as using “auto insurance quotes” or “auto insurance company”.

Paid Linking Schemes

Google frowns upon paid linking. According to their website, “buying or selling links that pass PageRank is in violation of Google’s Webmaster Guidelines and can negatively impact a site’s ranking in search results.” But still, the temptation to pay for links is hard to resist.
Paid linking comes in all forms including reciprocal linking, link networks, and triangular linking. Reciprocal linking is becoming less used because Google has become more apt in detecting this practice. Meanwhile, the search engine is developing a method to effectively prevent the other two as well. Triangular linking is a non-linear linking strategy.
Site X links to Site Y, and Site X will get a link back from a site from another site controlled by Site Y. Link networks are more complicated because there are a number of controlled sites. The group has non-unified relationships and links can quickly be added to participating sites.
Overall, trying to cheat the system is not likely to pay off over the long term. It is always best to pursue natural links that come from people who simply want to share the information from your website.