I think it depends on a lot of factors. I think judging by the seemingly tireless efforts of us fans the past couple of weeks to (seemingly) no avail makes me think the real factor is the mtv watcher that comes across the song on the radio or on tv and thinks "hey this is cool" and then goes and votes for it.
I also think the types of videos that are on already affect the voting. And I also think voting will increase when mtv and vh1 actually start PLAYING White houses in their regular rotation.
Don't get me wrong, the song has just recently been released and so has the video, so it will obviously take time, b/c VC is not a Britney or Eminem that automatically gets heavy rotation. I am just curious when everyone thinks things will start to fall into place, as we continue our efforts.