Intros are hit or miss depending on your videos. Intros are good because when people see a video, they know who it was made by and where they can go if they want to watch more videos). If i am doing a video thats part of a series (like my monthly top ten fun things to do videos, or my big project videos) i put an intro. If i am doing a smaller vlog or something for my fans (like opening fan mail, talkning about future plans) then i don't. Also, keep it short (like 3 seconds).