Several websites offer money (after a minimum level of earning) by clicking on advertisements. Hence, they are called paid-to-click (PTC) sites. One has to get registered before the project begins. Not all of these sites could be genuine, so be careful. One may also refer friends and earn money in the process. Some such sites are ClixSense.com , BuxP and NeoBux are some of such PTC sites.
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.
Sign up for a reputable affiliate network: Aside from Amazon, there are dozens of large reputable affiliate networks, such as Share-A-Sale, Clickbank, and Skimlinks, that specialize in connecting you with merchants who are looking for affiliates to sell their products. They charge relatively low commission fees for the privilege of connecting you with merchants, and the merchants on these sites tend to offer much higher commission percentages or set dollar amount payouts.
If you’re looking for inspiration, my friend Michelle Schroeder-Gardner of the website Making Sense of Sense has become the expert on all things affiliate marketing. Michelle earns more than $100,000 per month from her blog and the bulk of her income comes from affiliate sales. Michelle has had so much success with affiliate marketing that she even has her own course called Making Sense of Affiliate Marketing.