Amazon Mechanical Turk - The online market place for work.
Labelbox - Build computer vision products for the real world
Crowdin - Localize your product in a seamless way
CloudFactory - Human-powered Data Processing for AI and Automation
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.
CrowdFlower - Enterprise crowdsourcing for micro-tasks