Honestly, and this is going to sound like utter bullshit, I never really watched trailers before doing RWEP. I read previews though, and previews can get me interested in a game.
However, speaking of this, you made me think of something that occurred to me the other day. I get very varying view numbers on the RWEP videos. I don't think this has much to do with the quality of each video, if it's funny or not, it's already too late as you've watched it. So what does affect the numbers.
Basically, player awareness of the game. If people know about a game they'll search YouTube for trailers or reviews and might stumble across one of mine. This is further confrimed by the fact that most of my vids get a spike in numbers in the week of release, as people look for reviews. So in other words, I get a very interesting inside look at how well known and searched for certain games can be.
The reason I was thinking about this is because of Red Dead Redemtion. Like I said, most videos spike once they've been released. RDR still hasn't been released and accounts for about 10% of my total video views, which is unprecedented.
In other words, whatever Rockstar is doing to hype RDR seems to be working incredibly well. People are aware of the game and obviously massively hyped for its release.