Seasonal jobs that might turn permanent - 9 months and counting

A staffing agency says some roles convert to permanent after 3 weeks. There are 3 people counting on me, so I am trying to be careful. The pay is hourly with weekly deposits. Has anyone been converted to permanent?

Keep a list of supervisors' names. A reference from one of them helped me land my next job.

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.