Well, what kind of companies do you work with—a printer, and a distributor? Any others? How did you find the ones you work with—and how did you know that they were the right ones? What have you done for marketing—gone to trade shows, paid for advertising, giving samples to the right people, or what? How well is it doing? Have you sales been steady, increasing, or was there a big burst at the start, and a trickle since? Um... that's what I can think of off the top of my head.
Roughly how much did you have to invest in the first couple of sets? Most manufacturers have a minimum order, and I imagine that would be the case for you considering you were getting something custom made.