I agree, it does give you an advantage, However the best items should be obtained by playing the game, not just by dropping a bunch of money.
For an MMORPG
Game shop NPC < Charged irl money < Boss drops
This is so players feel, hey i can be the best without paying money. aka: I’m not being “cheated” into a money trap.
Money helps the game, but like jason says, plastering it all over the game just says i’m in this for just the money.
Also, paying for everyday items is terrible. An RF online server reduced the drops rates of everything so much that it’s impossible to break even. and you have to charge to buy potions.
Atlus online’s game Knights of the sky is full of abandoned accounts because you had to pay to refill mineral mines at one point, either that or the game stops for you.
Both are pretty much abandoned at this point.
Now ADs is a little different. what most bad advertisers seem to not realize is there’s a difference between looking and seeing.