I think you're right that a plugin install is smarter than trying to get people to stop going to Google. I think you need to make it very clear why it's worth installing the plugin initially. Something concrete that we all wish Google did.
Reassuring people that the plugin is lightweight and won't compromise their security is also very important. The history recording might be great, but it sounds creepy.
I don't know if it's true, but a dark themed web site might not be a good idea when trust is important. A/B testing on install ratio?
We've de-emphasized the history part though have kept it in the product since some of our users really love it. In the latest version you can completely disable the recording elements (you could always turn recording on and off).
Interesting thought on the dark background. I hadn't thought that the color might influence trust in that way, but definitely worth testing.
Our install wizard asks the user whether they want the history component or not since we figured it's best not to make any assumptions. History is only one part of the product now - that's what I meant by 'de-emphasized'.
Reassuring people that the plugin is lightweight and won't compromise their security is also very important. The history recording might be great, but it sounds creepy.
I don't know if it's true, but a dark themed web site might not be a good idea when trust is important. A/B testing on install ratio?