Spam is the biggest threat to organic search engines, whose goal is to provide quality search results for keywords or phrases entered by their users. Google's PageRank algorithm update ("BigDaddy") in February 2006—the final stage of Google's major update ("Jagger") that began in mid-summer 2005—specifically targeted spamdexing with great success. This update thus enabled Google to remove a large amount of mostly computer-generated duplicate content from its index.
Mechanical Turk is Amazon's take on micro-jobs. These are small miniscule-jobs that you can do for other people, which they call HITs, or Human Intelligence Tasks. These are super simple tasks that anyone can do. Some examples are listing off some URLs with certain kinds of images for one cent, or recording a few phrases with a microphone for 6 cents.
Raise your hand if you love the idea of earning extra income or ditching office life to learn how to make money at home. Well, you're not alone. According to a 2017 telecommuting report by FlexJobs, the number of U.S. employees who worked from home at least half of the time has grown 115% in twelve years, from 1.8 million employees in 2005 to 3.9 million in 2017.