What's best? Long Videos or Short ones?

Hey there,

I'd taken a break from putting up vids for some time and am now
re-examining my approach. Alot of my videos were upwards of 3-9 minutes
long and well, I just realised that they may be boring as well.

What do you folks think? Should one stick to shorter vids, say a couple
of minutes or less? What do you folks put up? How long are they?

It's hard of course to gauge any of this without some sort of system
(rating or otherwise) that tells us how many folks have visited our
vids and what they think of them.

Any thoughts?