Blizzard created a simply abusive system for storing characters in the online game. You could spend hundreds of hours building characters, yet the system only allowed them to remain stored if you played them every 90 days. Come back in 100 days, and your characters were permanently gone, no option for restore, even for money.
I spent years trying to remember to refresh characters I'd spent a long time on, then forgot one of two accounts and lost those, then spent more years on refreshing the 'main' account and then lost it also. There's really no excuse for the original design. Since this is a review, I'll mention Diablo II probably has my favorite game theme music ever, and it was just written by a young worker at Blizzard.