The website is very unclear. What sort of data? Who would be cleaning the data? What type of data cleaning? What types of payment? How is access to the data controlled? How is the data cleaned? Are extra data views to help data cleaning provided by the site? How are bandwidth concerns addressed? What does user karma signify? etc etc.
We can run your user data by our AutoML tool <a href="http://ForecastApe.com" rel="nofollow">http://ForecastApe.com</a> and add a predictive power estimate to each dataset. In fact it is like adding a dollar tag to their data. So they could thus justify cleaning it.