Should standard model releases give % of sales?

I posted this question on a certain modeling site and some people seemed awfully freaked out by the notion and some were particularly troubled by the idea of having the whole deal with a model spelled out in one document. They seemed to think it would take two. I’m going to write something more article-like and less journal-like on this at some point, so I’d love to know what other folks think.

For many years, my standard boilerplate model release for nude shoots has given models a royalty % of any significant lump sum sale to a third party. If I pay a model at the time of a shoot, this counts as an advance against future royalties.

To me, this seems fair.

A lot of times, at the time of a shoot, you don’t really know what the images will be worth.

Giving up rights to place images, in order to do trade, seems very wasteful to me. What if the work is great? As an artist, I want my work seen. But, if the work turns out very valuable, it seems like all parties should benefit, not just the photog or just the model.

It seems kind of like bad math to pay a model $75 an hour to pose nude or semi-nude for artsy shots when the photog has no idea who he or she will sell the images to and odds are good it will be for less than that.

But it also seems unfair that, if a photog does get a windfall profit from photos of a particular model, the model does not usually share in this.

Should standard model releases give models a % of a photog’s sales?