Similarly to Facebook, Twitter, or any other social networking site, an interesting profile is a must. If people like your videos, they will check your profile to learn more about you. When they see that your profile is boring, they won't bother more with you. You can make your profile a bit informal but don't make it as if it were the profile of a crazy teenager – you are using YouTube for business, right?Your logo and your website URL are your major branding weapons. This is why you must include them in the video. You can include them in the beginning of the video or at the end. It is best to have your logo and URL throughout the whole video because this way you will be gaining lots of exposure but if you can't do it (for instance because of artistic considerations), the beginning and the end of the video will suffice.