I don't believe you can't get popups just because you use a Mac. The reason why popups are more common now is because ever since Microsoft started adding a popup blocker in Internet Explorer, computer programmers were forced to find a solution around popup blockers.
I believe the next version of Firefox is suppose to have a better popup blocker. You should go to thier official forum to find out for sure.
http://forums.mozillazine.org/index.php?sid=184a70a4b30e5c68f99f6af8ddfa5465
Getting rid of popups is a constant back and forth struggle. Programs that block new popups will eventually become useless once the popup programmers learn how to work around them. This means that an updated popup blocker has to be created to block the new types of popups. The whole cycle begins all over again.
I believe the best way to stop popups is to never click on one and make sure everyone you know doesn't click on one. Part of the reason why they keep doing this is because they will get enough people to click on their popups which makes it worth advertising with popups. Anyone who clicks on a popup is punishing the rest of us by telling these companies to make more popups. If it doesn't work then they would not use it.