I'm bored of people not even understanding the use of this extension. Basically (and please read VERY carefully the next 6 words) it _*blocks the so-called "good" popups*_, see here : http://www.popuptest.com/goodpopups.html
***Note about Firefox 4 PARTIAL compatibility***
Due to popular request I'm marking this as compatible with Fx4 so the people who want to keep using it aren't punished because of the ranters. Note, however, that some features (keyboard shortcuts) are broken. They don't cause trouble, they just don't work. I'm aware of the issue and I don't know / don't have the time to find out how to fix it.
***Very important UNINSTALLATION instructions***
For a successful restoration of your former popup settings, please use the uninstall procedure described in the "Uninstall" tab of the "Settings" window. It's very simple and works fine... unless you don't use it, of course... If you forgot to use this uninstallation procedure you can still restore your settings by reinstalling the extension and running the procedure.