Originally Posted by
Saab Dastard
Are you sure they prevent the download, or just prevent them from displaying / executing?
Usually, the ad is an image, which takes up significant bandwidth. AdBlock has its own blacklist that is updated, and yes, it does stop embedded ads from being downloaded if they are caught by the filter. More details in their
FAQ.
With NoScript, it depends on the ads and how you configure it. I use it to target 3rd-party stuff specifically. and so I enable the "top level domain" option. This always allows scripts from the site that you navigated to, and blocks all others, unless you've created an exception either way. Some of the blocked scripts would have been downloading and displaying ads (among other stuff), so yes, I call that a major bandwidth saving.