The Hillary video was posted to YouTube on March 5. Talking Points Memo and Huffington Post linked to it the same day. They generated a little more than 23,000 views between them.
It didn't go hockey-stick until yesterday when it started airing on TV News. And who do the TV news desks follow like sheep? Greg Sargent on the TPM Horse's Mouth blog tells who. Matt Drudge posted it late Sunday evening. And that when the TV networks got interested.