It wasn't when I was subscribed directly to Marvel about seven or eight years ago. They mailed me each comic I was subscribed to in its own plastic bag with a card stock board behind it. My address was printed on the board.
Mind you, I have absolutely no idea how third-party online comic shops handle subscriptions. I've only ever ordered from Mile High Comics, and never actually subscribed to anything through them. For the individual orders, I know they put all of your comics together in one big plastic bag, then mail that to you in a box with pretty good packing. I've never gotten any damaged comics from them. Again, I've never subscribed to any online shops though, so they may do subscriptions differently.