I have a couple long term, open-ended contracts right now that I'm consulting on, billing out anywhere from 10-40 hours per week on each. The deliverables are frequent, communication is open, I invoice every two weeks with detailed line items, and get paid within 7 days. There are no up front deposits - honestly, it goes against my own values, I'm uncomfortable getting paid for work I have yet to do. The terms are clear in the contracts with work stoppage clauses and all. It's worked well going on about 6 months of doing this. Maybe I'm lucky, and maybe this is the nature of doing long-term gigs or just having clients you mesh well with, but is this really all that unusual?