Are there any legal pitfalls I should know about when creating a service where I pay users to provide a service to customers? The model I'm thinking about is like Amazon Turk for a certain vertical. Users will sign up and then be able to do short jobs. They'll earn a few bucks per job, then at the end of the month we'll pay them for the number and size of jobs we did. It might be anything from 1 to a few hundred.
Am I right in thinking that these users will be considered contract labor?
Are there any problems that can arise from paying people outside the US (which is where I am)? Or for witholding payments until the user has earned a certain amount (say $500)?
I realize I'm going to need the services of a lawyer to set this up, but want to know if there's some huge problem I'm overlooking before I put a lot of time and money into planning my business on this model.