> > Who made this decision
> Nobody.
This might be true for AOL; I wasn't there except as an early/beta customer -- something like 25% off their hourly(!) fees for life! :-)
But at HBO this was absolutely a choice. We had @hbo.com email addresses; it was a race among all the TW siblings who would jump on the @aol.com bandwagon fastest, and our CIO was eager to win that race: we were among the first to switch, and it was a pain in the ass. As one example, there was no good out-of-office functionality. I had built that for HBO in the mid-'90s on MS Mail for Mac, so regressing that hard was a bitter pill.
As another fun piece of trivia, I got one of the "blueberry"s -- a blackberry purpose-built to work with aol.com email addresses, and housed in dark blue translucent plastic instead of black. Good times...