#1 Link Building with “Rented” Paid Links
Nowadays, paid links are strictly forbidden by Google. However, once upon a time, link purchasing was the lifeblood of black- and grey-hat SEO. It was effective and cost-efficient.
Basically, “rented” or brokered paid links are links that you use for a limited period of time. When your “rent period” is over, you can either rent the links again or they’ll go back on the market for other SEO ninjas to purchase and use them for their sites.
Obviously, this can be seen as cheating. SEO pros could keep their clients on a tight leash, making sure that they would never get rankings high enough to stop investing in links. For the better, Google put a stop to that kind of cheating.