So, you found a need, but are having trouble getting paid? Very common.
Two things: first, a reward for actually completing a phase of the trial and second, a personal phone call. The reward can be a White Paper, eBook, etc. Something that shares your expertise but doesn't cost real money. I also like surveyGizmo, but use it very carefully... most people hate endless questions.
On the call, offer to walk them thru the actual sign-up. Before you tell me it won't scale, so what? You have to figure out EXACTLY what people will pay you to do for them. Then pour gasoline on the fire.