Adblock Plus

I've used adblock for a couple of months, but i stopped using it, when I noticed it doesn't even block popups. I've got way more popups now, then I had before I installed adblockplus.

If you get the same pop-ups on all sites, your system is most likely infested with malware. You might be able to find a removal guide if you search the web for the product that's advertised, or some other keyword that always appears alongside the ad.
http://malwaretips.com/blogs/remove-mac-os-x-virus/

Also, it goes without saying Adblock Plus won't block anything when it's not even installed.

see also
http://www.thesafemac.com/art/