Are you using video on your website? Have you really given thought to how you're going to deliver that video—and the consequences of using free sites to host the video?
Video is bandwidth-heavy, so I can't fault you for off-loading that content to a service that serves it up for free. But, as your grandfather said, "there ain't no free lunch." Services like YouTube are in business to make money and to make money they need to keep you on their site. Often they'll do that by showing additional content that's available for your viewing pleasure.