Everybody as to have gaffers tape to produce anything, and you can find it (almost) everywhere. So, the only advantages (in my mind) that a vendor can offer are based around actual availability and price. When others are out of stock, T.O. has it - and at a price that I have not been able to beat anywhere. 'Nuff said.
Like to have other colors rather than black, but....
for everything - securing cables, fixing wardrobe, securing mics on both people and places, fixing broken tripods, holding splash pans on cars (seriously, unfortunately), and more