There are many companies which are micro-freelancing marketplaces where many people do simple repeated tasks and get paid for their work. In this post, we are listing top websites in this field.
Amazon Mechanical Turk is a marketplace of simple tasks that can be easily performed by humans but are complicated to be performed by a computer. Simple tasks are called HITs (Human Intelligence Tasks) which are created by employers with fixed monetary benefits. A turker (or contractor or worker) can perform these tasks and get the money transferred to his account
Microworkers are one of the best Mturk competitors with hundreds of jobs available each day. It also pays relatively high to their competitors.
Rapidworkers are also in this space mainly providing marketing related jobs. Rapidworkers are combining Workers and Employers to minimize publicity and marketing costs while at the same time providing money to users to perform that task.
Minijobz is another player in this category. You will get $1 just to sign up.