Make combination of both.
Mainly keep your files free for download, but the best or the rarest make only premium.
In that way you will keep visitors happy with free download and also make them spend money ;)
Since is almost impossible to start posting with new account (you will get spammer ban after few post or eternal waiting for your thread/post to be approved) I'm selling PornBB accounts with one star or 100+ posts that will allow you to post without any problems or waiting for approval.
I'm selling 5 years old adult warez blog - nastyplace.org
Most of the traffic is referral traffic and from tubes, so there is a huuuge room for organic traffic improvement for witch i don't have time or the will since I'm occupied with my offline business.
Website get around 1-2k...
I'm selling links, banners or blogposts on 2 of main adult websites:
Links will be placed in Our Friends and Our Partners section on sidebar (so it will appear on homepage and all other pages) so you will get good traffic as well as SEO benefits
Banners will also be placed in sidebar...