Google (NSDQ: GOOG) continues to strike deals to up the amount of professional and long-form content on YouTube, but it’s simultaneously pursuing a more straightforward strategy in order to get more money from the site: It’s trying to get YouTube visitors to watch more of the content that’s already there. It doesn’t seem exactly like a big problem, considering that YouTube visitors watched an average of 67.8 videos last month, far more than any other big video property, according to comScore. But in a WSJ article, YouTube director of product management for advertising Shishir Mehrotra says, “As a general statement, we believe that the best way to grow revenue on the site (is) to do a great job growing traffic on the site.”