> - Keeping a free plan with limited space / limited quality (and no hotlinking - not sure you allow this)
We did this already; it pissed off the fans and the freeloaders came in any way. Double loss. This is already less than they had.
> - Separating albums between regular/+18 pictures (so if in +18 no google ads/outside of robots.txt permissions, etc)
Well we don't allow adult at all and we don't want to. People just upload them anyway and because of the thousands of pictures coming in all day and night, we cannot screen them. Well we can manually, but then it would be even less feasible to run this.
Accounts could be NOINDEX until they are a certain age or get to a certain # of images, and then they get reviewed by hand. You can review by hand using crowdflower or mechanical turk - it's pretty easy to show the first 20 pictures (or whatever) in small, and have a large button. You can optimize the interface to make it very fast, as well.
> - Keeping a free plan with limited space / limited quality (and no hotlinking - not sure you allow this)
We did this already; it pissed off the fans and the freeloaders came in any way. Double loss. This is already less than they had.
> - Separating albums between regular/+18 pictures (so if in +18 no google ads/outside of robots.txt permissions, etc)
Well we don't allow adult at all and we don't want to. People just upload them anyway and because of the thousands of pictures coming in all day and night, we cannot screen them. Well we can manually, but then it would be even less feasible to run this.