We operate with an ad network of more than 1 million publishers (i.e. websites). Your site is shown as a pop-in (which is an embedded window to the publisher's website) while the visitor is browsing the publisher's website. The visitor must decide whether to continue browsing in your site or close the window and continue browsing the publisher's website. Every time your site is popped-in the publisher's website you have received a real visitor to your site. We consider this to be the most effective method of advertising and provide the best return on your investment.
You can find more information here: http://www.fulltraffic.net/advertisers/guide