Your preferences!
Does it matter where you get it from? Do you like getting it from a name brand or do you get it from the bulk supplier?
(Ex. Creatine HCL from Con-cret 48 servings for $28.98 vs Creatine HCl from Nutrivitashop 300 +/- servings for $29.00)
With a big difference in servings for price, do you sometimes wonder if it's a good quality?