Your reply changes the definition of "opt-is". He's not saying "Hello is opt-in because you can choose not to use an active feature if you don't want to", he's saying it's not enabled unless you actually use it by clicking on it, otherwise it is an inert feature that isn't doing anything. You have to take actions (opt in) in order for it to be active. If Firefox included an extra theme with the download, but I had to specifically go in and choose that theme, it would be analogous. Ask Toolbar is not analogous, because it is operational as soon it is installed.