The reason you see all the web site based dvds out there is because those companies are all dumping huge numbers of new releases at super low catalog prices. They are all trying to claim as much shelf space as they can and essentially are in a race to the bottom.
Here is what you are looking at...
The distributors all produce their own product. They take on production company xyz to distribute xyz's videos but in reality they are only using xyz to be a loss leader, sold ridiculously cheap, so the distributor can get its own products out on the shelf at a higher price. In this environment, companies are lucky to see even a few hundred sold since there is such a glut of cheap new release. And by cheap I mean like less than a dollar per title.
If you have 400 scenes, imagine how much Gamma or Mindgeek or PornKings or Homegrown has...
Now figure in that there is going to be at least 90 days before you see a dime on the investment of replication, mastering, boxes etc for a return of pennies on the dollar. Good luck. It is a recipe for disaster unless you can find a way not to get burned by the distributor. You could try to work out a deal where the distributor carries all the overhead upfront, but good luck - since there is no form of third party tracking you are even more at their mercy. Better to just license them the scene so you get paid upfront.
We have worked with all the US based distributors and I really don't have a single positive thing to say about any of them.
You could of course try to distribute yourself direct to stores but many of the stores are tied to the distributors so that is a pretty steep hurdle as well.
I could go on but I think you get the point.
