YouTube is burning a hole in Google’s pocket because of bandwidth costs, but at the same time the video website is making a solid amount of money these days too. According to Citi’s Mark Mahaney, YouTube should generate over $3.6 billion in gross revenue this year. YouTube’s current traffic growth is 20% quarter over quarter. Mahaney is bullish about the early results from YouTube’s “channel” project. Mahaney said that his 2012 revenue estimate ?is likely 50% greater than Yahoo!?s Display Advertising total and right-in-line with Netflix?s total subscription revenue. We really doubt whether most investors realize how big/important YouTube has become.?