If you wish to promote your website to the adult users but do not have an advertising budget to support it then you can still get free adult traffic. Many websites use the free adult traffic exchange programs where they exchange the traffic among the network and are able to generate traffic for their own website without spending anything. You can also use traffic sources like link submission, promote your website through social media marketing, and use various other such ways. If you want quality traffic and have an adult traffic based website then signing up for the free adult traffic exchange programs would be more useful.
When you sign up with the traffic exchange programs then you basically are willing to send the traffic that you receive at your site to other website in a network. The other websites in the network also promotes your website by advertising your website on their page. This helps you to get their traffic also and promotes your online business. You can buy the popunder ad traffic through this as that helps you to promote your website to the right traffic and that too without any charge. Popunder ads have a good success rate and are noticed by everyone easily.