When it doesn't it's usually because of preordering too late( week of release) or issues with their credit card, like it expiring. I wouldn't worry about it, and I preorder every game I buy on Amazon
I've preordered tons of games from them, and I've never had a real issue. I've had some items say that they weren't being delivered and suddenly get them on my doorstep on release day without warning, and I've even gotten a couple games early, like Puyo Tetris.
Maybe I'm old fashioned, but I've never had any issue walking into a store on release day and picking up a game. The few times I pre-ordered (Best Buy sometimes has a $10 certificate for pre-orders), I just select store pickup.
Amazon was late delivering all of my preordered games. I ordered them on the first day of preorders. I had my console and no games. Since switching to Best Buy gamers club, I've had no issues. If you don't care about getting it on release then Amazon is fine. I've had Prime for years and never had an issue until this incident. I walked in to Best Buy and got the games and shipped all my "late" games back to Amazon. Amazon has become reliant on the US postal service and it just so happens that our local office is terrible!
I pre-ordered my Splatoon 2 through GameStop and it's fully paid off so I'm just waiting. Also payed in full for the inkling girl and boy!! I can't freakin' wait!!!! #PoundSymbol
I've preordered mk8d from them and on release it hasn't shipped and no ship date so I had to go to store. I preordered month ago for splatoon 2 and it actually says arrival date so here's to hoping