Originally Posted by NetRodent

You'd be asking for trouble outsourcing this sort of work, especially if its through an agency. Of course, if its a small niche, it might be worth the risk.

You can mitigate some of the risk by dividing the keyword list for a niche over several workers. You're also less likely to get screwed if you hire low end data entry types and mislead them somewhat about the nature of the work.

For example, don't tell them you want them to clean a list, rather you want it to be categorized. Tell them you're working on a thesaurus project.