Probably corporate. Compare, sometimes third party outlets run special promotions that work better for you.
Word of caution with third party dealers.... Ask about charges they do. I just had one sneak in $9.99 set up charges per line. That is their charge not Verizon. Verizon is going to have a $30 activation charge on your next bill. So ask about the charges they charge. I paid the $9.99 set up because it was still better deal then Verizon had, but I wouldn't have if it was exact same thing Verizon was offering. So like I said, compare them, get the best deal you can.
I used to be strictly corporate, but with the elimination of contracts, and early upgrades are hard if not impossible to get from corporate, they made it so where you buy a phone doesn't matter anymore, so go where you get the best deal IMO.