Well I don't want to give away my niche or url's, but i'll give you an idea on how I do it.
I buy my domain names at Buydomains.com.
The cost is $16 per year. (2 year min.)
They have a feature where you can redirect your domain to any url. Another great feature they have is a way to LOCK your domain name in the browser, so no matter how many pages a visitor clicks at your site, your domain name stays in the browser.
What's so great about this feature is MOST search engines will be fooled into thinking your submission is a real website and not a redirect. (Meaning your domain name will be submitted and NOT the redirected web page.)
Meta tags are also another feature included. Where your title, description and keywords will appear in the search terms. Submit the url with www. and without you'll get listed twice.
When someone clicks on your domain name from a search engine, they will be sent to your redirected url.
Now, if you already have a hosted website, just set up a message board on your site. If not, there are many free message boards you can search for at your favorite SE. Make sure they accept adult content OR discussions. Most don't mind adult topics, they frown on boards used just for posting adult pics.
Now if you can find a message board where each posted message does'nt have characters in the url like ?%# ect., then these individual pages will also be indexed sooner or later on search engines. (More hits to your board.)
Now you don't have to set up message boards, you can send them straight to your sponsors, but the key is to get the visitor back to the board as often as possible. Then they will be comfortable ordering from your sponsors. Just make sure all your sponsors (2 or 3 at the most) are related niche wise.
Make a free sample gallery to your ***BEST*** sponsor and give them reasons to sign up. Don't ever send them straight to a sponsor. Tease them good. You can even use bogus testimonials with different email accounts you have access too.
It will take time for you to fill your board with messages, but in time you will. I'm sure you can find a way to prime the pump.

Then you can continue to order more domain names with the same niche and send them to your message board or site.
You can do this over and over again for any niche and each domain name will get listed with SE and you won't have to host any of them.
Believe me...each domain name will pay off. $32 for 2 years is a GREAT deal and investment. Hopefully Buydomains.com will keep this feature as many other registras are now doing the same..
Once you get a feel for it, you can do SO MANY things with this technique. No heavy bandwidth, the only updates are removing unwanted messages. No more circle jerks or thumbnail submissions unless you like the work.
There are lots of people making more money then me, but I have less headaches and a decent net worth.
Hope I was able to help alittle.