The recruiter sent me several positions and asked how I would fit into them. I spent a good amount of time (2+ hours) reviewing 7 different positions, raising questions, and answering questions with specifics.
The recruiter did not respond to me after I gave him the responses. He didn't respond to a follow up email, nor did he respond to a polite voice mail.
In short, these guys are unprofessional and will waste your time without even expending a modest amount of politeness towards you.