PopUp Exchange
In contrast to the bannerexchange, where graphics (banners) are exchanged, pop ups work with sites.
The user exchange the visitors among each other.
If the visitor accesses a participating website another window opens up containing the website of another user.
There are two different kind: The intro- and exit up exchange. The window containing the intro pop up opens up just after the site has been accessed and the one containing the exit up after the site has been left.