Rated 1 out of 5 stars
The Addons page description makes no mention that this is an ad-supported add-on. It's 2012, guys, you should know by now.
The options dialog opens immediately after installing, and the "optin" is presented. I declined to opt in, and uninstalled the add on. Nevertheless, upon checking the about:config, there was a "extensions.multibmtoolbar.optin" entry, and the value was "true".