Google tolerates cheating by adsense publishers,since it also paid, it is ruthless in destroying linksellers only.

The microjob websites are useful in understanding the value of various activities online
For example for retweeting or following a twitter account, the price is $0.02
For upvoting on reddit, the value is $0.03
Similarly for visiting a google adsense website, and viewing 5-10 pages the value is $0.03
However, google is so ruthless in destroying competition, that in the last 6 years, Google has reduced the value of a link, linksellers time to zero, hiring contractors to criminally defame the link seller, make fake claims the school dropout, call girl, scammer students, cheater, robber girlfriends of top indian government officials working in raw/cbi who do not spend any money on domains, own the domains of a private citizen,
So though there is some value in doing all social media activities, other than selling through a few ad networks, it is almost impossible to make money selling links, or blogposts online even for $0.1 since google is extremely ruthless in destroying link sellers, stealing their leads, correspondence.
In some cases, the google adsense publishers are cheating the google adwords advertisers, yet since google is also making money no action is taken against them for many years. The link sellers are not cheating anyone when they sell text links, yet because they reduce the money spent on google adwords, google is ruthless in destroying them.