Manufactures use to release a few new balls to selected staff members and certain high volume proshops.
Columbia has a program now called Elite proshops. It cost $700 a year to belong. With that you get 1 each of their higher performance balls as they are released. You also get listed as an Elite proshop, shirts, aprons, and other small goodies.
I know Brunswick has a similar program, I do not know about Storm, Ebonite, etc.