You're joking, right? The majority of your proforms are coming from shop employees.
It's mainly a program to get products into the hands of the sellers at a steep discount. People tend to sell what they use. Manufacturers have a vested interest in getting their products into the hands of the sellers. It's a mutually beneficial thing.
The snow industry is weird about it. Every industry has these discounts, but the snow industry acts like it's some cool, super secretive thing. It's not. Everyone does it.