There are various categories that collectively determine that final score such as digital, physical, etc., voting is just one of them.
Personally, I'm not too concerned about the MAMA, lots of folk are taking it less seriously each year. It's interesting to see who wins and many do get caught up in the excitement of the voting and such but I mostly look forward to the show (it's practically more of a music festival anyways).
The shady nominations and some previous wins...yeah I think it's pretty clear. Heck I mean, Lovey Dovey ain't even up there and it's still reigning as the most downloaded song of the year.
But anyhow, don't feel discouraged from voting though. Continue to do so as we still gotta support our girls! If they do manage to grab a win, it'll be wonderful and I know the girls will definitely appreciate it. :]
T-ara are up against my other favorite group, SNSD/TTS. If either win, I'd be very happy but if either lose, it's all good~