Just FYI, at some point iTrader is going to be completely uninstalled from this site. We have outgrown it.
It's going to be replaced with a new rating system that is based on the Instant Payment system we have in place. Essentially you will be able to still rate people, but only when the system knows an actual transaction took place (i.e. the seller would need to be using the instant pay ability if they want to receive any sort of rating). Essentially you can't give or get a rating if no actual money changed hands (no ratings for free stuff, reviews, fake ratings, etc.)
The system isn't completely done yet, but this is more to let you know what's going to happen down the road so there are no surprises. If you want to start building up your rating now, I would advise using the instant pay function.