stock video - is it worth submissions?

I've been signed up to stock photo and video sites for a while, but have never tried submitting footage yet.
I never really thought about it, until recently, when I discovered that two big advertising agencies that I have contacts in use i Stock Video for video resources... and it got me thinking that maybe it is more popular than I realised.

The problem with footage sales compared to photo sales on sites like i Stock Video and Shutterstock is that subscribers have to pay a lot more for videos, which makes sense, but also means that footage has to be pretty good to get sales.

However, with the amount of video that is used by people in advertising or creating video products that use multiple backgrounds in their work, it looks like stock videos are worth the submittion.

I haven't yet tried, but from what I've seen, anyone who can create interesting or abstract moving backgrounds should give it a go. Things like moving or animated fractals or lines seem popular, probably because not many people have the time or knowledge to make them themselves.

Anyway, if you are interested, check out i Stock Video or Shutterstock footage