Hi,
I suspect your friend spent a little money to get his results.
The number one way to get hits to your website is google adwords: http://adwords.google.com/select/Login
Basically what happens is google will feature your website when people search for a keyword attached to your website. If you have an adult site the keywords might relate to a particular festish you feature on the site, plus general words people use when searching for adult sites.
You pay around $0.10 any time someone clicks on your site. That might seem like a lot of money, but you can put a limit on how much you want to pay each day. Plus, you have to assume that a percentage of the people who go to the site will become paying members, so you'll be paid back for your advertising.
Once you have a lot of traffic going to your site you can then charge people to advertise on your site, thus making even more money. So if you want la lot of traffic quickly, you have to invest a little money, but you'll get the results and hopefully you'll attract people who will keep returning to your site.
Good luck!
Gina
Internet Researcher
BA Music and Philosophy, Dance/ Health&Fitness/ Travel Guru