It's okay to post earlier than the 72 hour rule when you're adding more content, but please avoid it when possible and try not to post more than once a day. Posting saying you're going to post again later in the day is a bit much.
Yay! One of my Youtube videos got to 100 views (in 2 days)! This Youtube thing is great, it's like the profile posts except I get to annoy entertain more people at once! Now I just have to practice my "Leave a like and hit that Subscribe button" shilling technique.