Hello there, this project is in a very competitive market and to get a lot of traffic to it as you have stated is going to require a lot of time investment and PPC investment along the correct channels if you want good, targeted traffic that will reap the rewards and give you a good ROI.
My company has worked with a couple of adult based businesses in the UK and US, so we know what this market is about, a firm strategy which leverages all the important channels will be put in place to ensure the best possible results.