Platforms like mechanical turk. Many workers do simple tasks for a little amount of money. Often tasks get done more than once and the result most of the people gave, is taken as valid.
http://mturk.com http://clickworker.com/ http://microtask.com/ Mainly Digitizing http://samasource.org/ non-profit, content moderation, digitization, data entry, Data Mining and Enrichment, Business Listing Verification http://cloudcrowd.com/ "CloudCrowd provides Turk functionality and adds workflow functionality and innate quality control" http://www.mobileworks.com/ quality through exclusivity
Because mechanical turk can be difficult to use, other platforms help people to structure their tasks and get better quality. They use mechanical turk as a ground layer and built upon it.
http://crowdflower.com/ uses mturk and samasource http://scalableworkforce.com/ uses mturk http://www.crowdguru.de uses clickworker http://smartsheet.com/ collaboration tool with crowdsourcing provided by mturk and livework http://www.serv.io/ media services, powered by CloudCrowd http://houdiniapi.com/ “provides a bridge for integrating crowdsourced labor directly into applications using an API.” http://cloudfactory.com/ uses their own trained workforce (Cloud Workers)
One person does the task. But the task can be split between many or done more than once.
http://www.optask.com/ Web Research, Marketing & Lead Generation, Procurement, Powerpoint, Excel and Word, SEO and Blog Writing http://mediapiston.com/ content creation http://newspepper.com video, photography and blogging services http://textbroker.com/ text http://livework.com/ Callcenter, Support (not exactly simple tasks) http://becomeaguide.chacha.com/ questions via SMS http://www.sumbola.com/ 'helps content creators deliver their creations to a global market' http://studentoffortune.com/ homework help http://www.content.de/ text (german) http://taskarmy.com/ “hybrid between odesk and fiverr” http://crowdmug.com/ requesting photos of places http://www.asksunday.com/ personal assistant
One or more persons use their expertise to fullfil tasks. http://10eqs.com Knowledge exchange (they structure the problem and have their own experts) http://eclerx.com/ Sales and Marketing Services, Financial Services http://starmind.com/ A bit like a bad quora with money http://g2link.com p2p risk management http://www.trada.com/ search engine marketing done by a crowd http://boostctr.com/ search engine marketing optimization http://www.taskus.com/ http://www.mavenresearch.com/ consulting https://www.minutebox.com/ expert advice over video http://work.io Our approach is to find the right persons for each task and to show people only tasks relevant to their expertise. Not live yet. Ask me if you have any questions.
There is a call and many people respond to it. There are different systems who gets a prize and what happens.
http://99designs.com/ designstuff http://www.mykindacrowd.com /ideas & problems http://www.hiretheworld.com - Creative Contests and 1 to 1 employment platform for Design, Writing, Programming, and Administrative Tasks.
Services specialized for translating.
http://mygengo.com/ http://www.tolingo.com/ http://www.lingotek.com/ http://www.smartling.com/ http://www.onehourtranslation.com/ http://strakertranslations.com/ http://www.speaklike.com/ http://tran.sl crowd sourced translation engine
Services that are built around offline tasks. From grocery shopping to repairing windows. Sometimes also online tasks.
http://taskrabbit.com/ http://agentanything.com/ http://gigwalk.com/ http://www.milk.ly/
#Freelancer
Platforms which help to find the right person for a job. Sometimes they also help the client to have more control.
http://elance.com/ http://freelancer.com/http://gur... http://odesk.com/ http://scriptlance.com/ http://vworker.com/ http://expertbids.com/ Professional services "get free personalized bids" http://biddyon.com.au/ http://www.voices.com/ voice over jobs http://www.canyoucode.com/
These platforms only connect the client with the worker. There are easy tools to built such a platform, as a result there are many. Tasks are often stupid.
http://fiverr.com/ http://fourerr.com/ http://gigbucks.com/ http://gighour.com/ http://gigme5.com/ http://tenbux.com/ http://twentyville.com/ http://uphype.com/
The title says it all.
http://softwarejudge.com http://epinions.com http://reviewme.com http://reviewparty.com http://reviewstream.com http://www.utest.com/
Many of these platforms could be listed in 'Simple Tasks', but I wanted to separate them because most of the listed tasks are only targeted towards spam. Like "follow me on twitter, like that page, submit your data to that site,...". (Sorry, if I put your company here. That is what I saw. I could be wrong.)
http://jobboy.com/ http://microworkers.com/ and http://minifreelance.com/ (not sure if just a copy or the same company) http://rapidworkers.com/ http://simpleworkers.com/, http://minijobz.com/ and http://www.desklancer.com/ (look also the same) http://shorttask.com/ Research, Data Entry, Writing Design
Not enough information on the website and I didn't test them already. Or they are just different from all others. http://minuteworkers.com/ http://innocentive.com/ crowdsourcing ideas http://www.little-favours.com/ (Facebook App, small stuff) http://crowdengineering.com/ enterprise crowdsourcing solution with integrated community management http://cumulusiq.com/ Knowledge as a service; SAP Integration http://kaggle.com/ post data, let scientists analyze. competition style. https://atizo.com/ idea crowdsourcing (german) http://researchgate.net/ scientific crowdsourcing http://www.poptent.net/ video contest http://www.rippple.com/ funding, service and cutomers for startups provided by a crowd http://castingwords.com/ transcription http://store.exvo.com/teams http://www.copify.com/ copywriting http://www.imagebrief.com/ photos contest http://www.speechpad.com/ transcription http://txteagle.com/ sms based http://world4brains.com/ crowdconsulting