Selling paid links can damage PageRank or google ranking.

Many people are paying attention to blog marketing. I am not very knowledgeable, and only know a few things about it, such as various ads, paid reviews, and selling paid links, etc.

Selling paid links in the blogosphere should be considered quite a popular practice since many people are doing it. However, what I want to say is that selling paid links can harm your PageRank or Google ranking.

Danny Sullivan from Search Engine Land specifically wrote an article titled "Official: Selling Paid Links Can Hurt Your PageRank Or Rankings On Google" to elaborate on this matter.