IOnature, I'm in negotiations with a stock agency at the moment. They approached me and are very keen on carrying my HDV footage. Problem is they're only offering me 40%, which I consider low.
I have been meaning to send some stuff to oceanfootage.com for years, but still didn't get around to it. They offer 50% but charge a setup fee. Oceanfootage are way ahead on web searches but do they have the same links with the purchasers as the likes of Getty? Who knows. There's also a lot of competition on their site. I still plan to try it though.
There are agencies out there that offer 60%, which is generous.
I get direct enquiries sometimes from web searches. Licensed some DV footage the other day for a TV advert for a travel agency. They only used about 3 seconds and I got GBP £510 which was nice, so the possibilities are there. The "10 second minimum order" helped in that case.
As for licensing footage for my own productions... way out of my league. I couldn't even afford to license the pic I wanted for my DVD cover.
Footage licensing deals are great, as are those occasional pro cameraman jobs for TV or promo. Trouble is they just don't come along often enough (for me) and when the season starts here we're glad to get stuck into the relatively reliable income of liveaboard DVDs again. A typical liveaboard earns us about the same as a single day shooting for TV. Even then the cash runs out a couple of months after the season ends and we're back at the ATM drawing on income from my house rented out back in the UK. In a year or 2 we should be truly self-sustaining year-round.
By the way the best gig I've had so far was licensing my Reef Life of the Andaman DVD to the Spanish news-stand market, of all places. They sold 30,000 in the first 6 months and still going 
The royalty's very small though.
Building a reliable, self-financing business in underwater video is a long road, and very hard work, unless you're incredibly lucky.
