Setting the "entire price" just means being a marketmaker. I'm sure you are familiar with the concept. The "commission" would therefore refer to the spread or the take. There is real risk in this and competition, and anyone can feel free to get in there making a market with a tighter spread if they feel they can do so. Bet they can't. Lead generation is not a phrase used by anyone but the idiotic press, so that part is a strawman.