alot of GNC products enhance the amounts of sets in your reps, its inherit to the coding of the
matrix.
GNC isn't always bad, just go in there, be firm with them. I find that GNC sometimes has some of the best sales I can find, 30 dollars for 5 pounds of whey protein, thats a great deal that pops up. With GNC its alot of bullshit to wade through but if you can stiff arm the persistant salesreps that are more persistant than preachers spreading the good word, then you'll be fine.