I'm going to be starting an experiment with some of my blog properties and I'd like to have some input. Right now, all posts have a 30-second animoto video embedded that has been uploaded to youtube. I'm going to first diversify the video sources. But my main question is there a sweet spot for video length? I plan to run an experiment with four video lengths: 15-30sec, 30-60sec, 60-90sec, 90-120sec What is your experience in this? Also, do you have any input on best ways to optimize embedded video?