i have to disagree with this
i dont think that opening ads in a new window loses you visitors. If anything, its just an annoyance to your visitors.
I do my best to ensure that all ads are opened in the same window. If the visitor views the new ads they will probably end up closing the window with your site anyways.
If the visitor likes your site theyll come back anyways either by bookmarking, remembering the url or by going back on their browser to your site.
The bigger sites on the web dont open ads on a new window so why should we
