Upload & Sell: Off
You print to present your image to other people who are not glued to a computer.
When you go to a gallery/museum, prints are "real." I guess you would rather have a large LCD hung on the walls, but typically, people prefer prints.
If you only care about sharing your images on the web, then you have no need to print. If you are only going to show people images on a computer then prints don't matter, BUT if this is your final product, you can shoot with some pretty crappy gear, because, aside from pixel peeping, no one will ever see the quality of your images.
OT: After printing by different dedicated B&W systems and inkjets, I have gone to prolabs only. Home printing is a pain... it seems like it will be more convenient, but in the end, I've found that a reliable prolab was far easier than juggling inks, papers etc. When I printed Epson pigment, the clogs from hell took all joy out of printing. Yeah, I've given up "fineart" papers, but my photos look like photos and I'm happy with that.
Yeah, hit me! Of course I wrote in a harsh manner to get a discussion going. I'm sick and tired of this constant talk of that "what matters is prints". Really? How come photography matters more than most things to me, even though I don't print?