When items go into your bag in World of Warcraft they make different sounds depending on what they consist of. You can tell if something substantial has landed in your bag without even having to look away from what you’re doing.
I’m sure it’s a subconscious thing for many players in WoW, like a sixth sense; I know it is for me, because I can play a game like LotRO and have no idea what I have looted until I go to sell everything at the vendor. I rarely spend time reading over the loot window, and in WoW I don’t need to. I imagine there are many features like this, the little things that often go unnoticed, but when implemented well can make for a smoother experience in general, and a massive difference in experience to a new player.
Is it really any wonder that WoW attracted so many players from without the genre?