futuresky - 5:35 pm on Jan 31, 2013 (gmt 0)

There are already plenty of add-ons that block Adsense and others. This probably isn't going to make that much difference?

Thing is, users have to make a specific decision to install the addons like NoScript. If I understand correctly Click to Play will be on (blocking) by default. With Firefox having a 31% browser usage share, could be a big hit to adsense (or other similar ads) maybe?

A couple of quick stats I've found:
About 450 million people use Firefox
Adblock Plus, the most popular add-on has 15,526,434 users (about 3.45% of Firefox users)
NoScript has 2,168,235 users (about 0.48% of Firefox users)