WoW doesn't cost $20/month, it's more like $15. Diablo is not an MMO like WoW. WoW has new content being added and game changes made all the time. There are hundreds? of servers to maintain. WoW has a persistant world with instanced content with more players than D3 will have.
I never mentioned Diablo 3 having a required monthy fee btw. I merely brought up what would be an 'optional' "Prefered Blizzard Account" with perks over a regular account. This would apply to all Blizzard products. SImply another method of revenue for the company that would prevent stuff like progressing our characters with $$$.
If you don't wan't to read my "complaining" then simply find another topic to look at. These forums exists for the fanbase to express opinions, even if they don't happen to be the same ones you have.
Most games nowadays have a source of revenue, Blizzard decided to use the RMAH its their choice and honestly i doubt anyone will be able to change their minds about it. Im not for or against anything in the game. im just stateing my opinion like the rest of you. and i do apologize about the "complaining" comment. I've played all of blizzards pc games from warcraft 1 to starcraft 2 and i beleive diablo 3 does have some promise in the future.
And yes WOW is always being updates, hopefully they will do the same with diablo 3 with all the money blizzard will be making and in the long run thats a good thing. Blizzard also have more projects in development too, with the extra money they can make these games better too. But its all speculation and I can't say what Blizzard will do with the money but hopefully it will come back to use in new games, and new content for existing games.