The next Thing would be that you are taking a Product created by Microsoft and earn your own Money with it. This is like WoW would be for free, but you're taking Money from the People for playing it. All other People would move to other Servers, for example we got many People from the USA and UK here, they would definatly go on the next best Server, because they don't want to pay or stay behind those who pay.
Also, I dont want to pay more as I already have to just to have Fun.
"Who is it doing this synthetic type of alpha beta psychedelic funkin'?"
Ive seen other 'free' MMOs with a donation system......
and they all go to hell because the big factions whose leaders/members donate often pretty much get what they want.
It may take a while but eventualy there would be an issue were faction A brings up 'hey we donated all this cash, we SHOULD win this war/battle and get a station in enemy space'
So yeah no.
Plus as mentiond Igiss has said no, which is what really matters!