Do I have to buy the game again for a digital copy?

Yes. In order to own it digitally, you would have to purchase it digitally.

H1GH0CT8N3,

If you already have a physical copy, there's no way to transition it to a digital copy. You would have to buy the game again digitally, and for value's sake I'd recommend selling your physical copy if you do so.

I personally like having a hard copy of my games, but recently I've been buying games through the Xbox store and by doing this you only get a digital copy. I think thats where we are heading, buying games digitally rather than getting a hard copy

If I know I am going to enjoy the game, I buy it Digital so I do not have to put the disk in.

I have GTA 4 and 5 for PC, Xbox 360 Disk (Special Edition) and digital, Xbox one Digital

Read Dead 1 - disk and digital - they get so cheap for 5-10$ I buy them again

Bioshock it is silly how many copies I have.

Yeah, that confirms it for me. I won't be buying another digital copy of any game again. This is the type of thing that trumps the convenience of digital downloads.