OK I know a lot of you have asked about how to stop the pop up because it can be a little embarrassing of you forget and leave your volume up and you are not at home or in a private environment.
This is what I just did tonight as a test. This is using Firefox.
When the banner pops up pause the video. Do a right click near the top and choose This Frame and then choose View Frame info.
When the other window opens click the permissions tab. Set open Pop up windows to block. Go down to Active Plugins and set Adobe Flash to block.
Since it's a flash video and these settings will only take effect for this site and wone effect other sites.
You will have to close your firefox and restart it for it to take effect.
I tested it and when the pop up does start it's blank except for saying this plugin has been disabled.