I need to agree with both Chris and Panky about their replies.
Marketing of pay site is generally a very complex task, there are many factors that take place at one time influencing sale of memberships together (also on the other side, there are many things/possibilities you should/could do to boost the sales).
Things depends on your budget and how much time & money are you willing to invest.
Lots of ppl are for example hanging around webmaster boards - you can do some good promo there even with less investment.
Other important thing is to have your affiliate program ready and working - so people can join. Give them a good deal, marketing tools, sample galleries or sample content so they can make the galleries themselves and promote you.
Once you're ready, a tool like Chameleon submitter will send the galleries you have to all relevant TGP/MGP sites out there and the good thing is that it will follow the individual TGP/MGP site rules..
It basically... 1.) saves the time spent looking for relevant TGP/MGP sites yourself.. & and 2)...it sends the deserved galleries to actual TGP/MGP sites fast.. so lets say, you can get your sample gallery to hundreds sites within a few.. its a great traffic generator for your sites and its good for promo.
You should consider using it in-house as a way to promote your sites (people use to do it themselves or they hire in-house submitters for them...). Also, other way is having affiliates use the above tools and let them work for you this way.. However, as Panky said, learn things first and then start working with tools.
On Chameleon Web page, there are nice interactive Tutorials available at
http://www.chameleonsubmitter.com/tutorials.php Those have been made in Macromedia Flash to show how to set up the tool, use the program properly and get the maximum benefit out of its features..