Providing advertising space does not increase visitor traffic. However, it does drastically affect your online presence. Firstly, of course it allows you to make money from your visitors. A good beginning program to do is www.google.com/adsense/ Banner advertising can sometimes be annoying to many visitors, however. Opening up your site to advertising also allows you the opportunity to engage in partnerships with various similar sites and perhaps do a banner exchange (inquire by contacting sites similar to your own) - in that respect, your site can be promoted through advertising.
If you want traffic, you have to have your links posted in many paid and unpaid websites. To get traffic, Post in Directories, social bookmarking, squidoo ... I mean there are lots of places where you can drag traffic from.. You can also get oneway links from high PR websites..