To provide a vaguely serious answer, digital has so many advantages. After getting a Vita, I was surprised at how digital focused my Vita has been via PS+, 8GB ten gaems megapack and my previous PSN purchases. I have a lot of digital shit now, I played Uncharted, Gravity Rush via PS+, played LBP and Wipeout via the megapack and played SOTN from a purchase I made before getting a Vita. Having a dozen gaems or so on the go is pretty sweet and convenient. I can play P4G than switch to Lumines than play Lemmings. It is really awesome to this level of flexibility especially when commuting during the week when I'll be in different moods after a day at the office.
Yes, there are many advantages (when done right), but sadly Nintendo doesn't really offer them all.
Usually the advantages are:
- Much cheaper to buy, even on release date (mostly true for PC games, but also for e.g. PS games when you're European and buy them cheaper on the US store)
- Convenience to just download it right away, you don't have to go to a store a wait for the mail to arrive.
- You don't have to change cartridges/discs and it's much easier to have all your games with you as you don't have to carry dozens of cartridges/discs.
- You don't have useless garbage in your room (unless you are a collector of physical things, then this is a disadvantage)
- With account systems and back up functions it's basically impossible to ever lose your games. (Even when e.g. Sony were to go bankrupt and would shut down the servers you could still play your games, because you don't need to be online to play them)
- Situational, but for example you can play your digital copies of PSP games on the Vita but not your physical copies (no UMD slot).
- Also when having account systems it's really easy to "lend" games to your friends by giving them your account data. It even works when you're living far away from each other.
- It's better for our environment (yeah, as if people would care...)
There are also some disadvantages
- You don't have anything in your hand/on your shelves (that's subjective, but many people love it)
- Currently you can't resell your digital games (but e.g. Microsoft currently wants to introduce a digital market to resell or trade back your digital copies so it could be a non issue in the future)
- You can't get them earlier than on the release date (not true for all retail versions as well, though)
Overall I think that even when we're heading to a digital future, companies should offer both digital and physical versions. Many people love physical versions, especially collectors editions which can be very profitable for the companies as well. Although maybe in many years physical collectors editions will include physical stuff and a box, but not the game on a disc/cartridge but instead a download code.
RE: Manuals; even when I buy a physical gaem, there's a good chance in not having a manual. My copies of Muramasa and P4G have no manuals. Which is a good thing cuz it saves teh Earth and all.
The Vita games usually have digital manuals and I surely prefer a colorful and detailed digital manual to the physical "manuals" we get nowadays.