wow, so people complain about $5 PER YEAR as being horrible to store AND transfer pokemon (people keep forgetting it's not JUST to transfer pokemon from an old game to a new game) but when you start a new game you can get your old pokemon right away almost at the start of a new game. (so you can breed what you want and start a new game with what you bred)
It's also future proofing yourself so you can keep pokemon through subsequent games and keep transferring up and as the years go by saving all those unique or special pokemon so that when future games come out you have something good that you don't need now to trade for one of those new pokemon that come out in future games. (I myself have two boxes full of legendaries, including 3 Zygardes, that while right now no one wants, in the future could prove quite useful. I remember in gen 3 EVERYONE had a Rayquaza because it was in every Hoenn game, but now it seems like everyone wants one and Zygarde will likely be the same in a few years)
HOWEVER, $5 per year is just a horrible, horrible thing, and people would rather spend the money on a second DS or yet another remake in order to get pokemon not currently available? the $40 spent on a pokemon game pays for 8 YEARS of Pokebank. Just saying. Seriously, a large bag of chips is $4. Perspective! ;-)