Mechanical Turk, a system for crowd-sourcing complex Human Intelligence Tasks (HITs) through parceling a large task and putting the parcels on a marketplace, has seen a recent resurgence, partly on the back of the success of easier to work with clones like crowdflower.com.
Given that on the Internet people find it easier to part with labor than with money, one way to monetize websites may be to request users to help pay for the site by doing a task on Mechanical Turk, made easily available as part of the website. Websites can ask users to fill out the kind of tasks they would like to work on as part of their profiles.
For example, a news website may also provide its users a choice between watching ads and doing a small number of tasks for every X number of articles that they read. Similarly, a news website may ask its users to proofread a sentence or two of its own articles, thereby reducing costs of its production.