MYXER.com-free ringtones..why does it ask if you have verizon??

I was on myxer.com just browsing around ad I notcied it said check if you have verizon..why does it need to know this? What difference does it make if you check or uncheck the box??

THANKS A ZILLION!!!

because verizon wouldnt let you download them at one point but now it locks them like you bought it