Amazon Mechanical Turk - The online market place for work.
CrowdFlower - Enterprise crowdsourcing for micro-tasks
SerpClix - SerpClix is a click exchange network used to send more real clicks to your Google SERP. You can click to earn money or buy clicks to rank higher on Google.
Bitfortip - Tip Bitcoins as an incentive | Earn Bitcoins for being helpful
Universal Data Tool - Machine learning, data labeling tool, computer vision, annotate-images, classification, dataset
Crowdin - Localize your product in a seamless way