Some theorize that it’s not the influence that makes the change in your subjects’ mind but what they tell themselves in their minds after the get your message. It will be beneficial if you knew what it was and if it’s negative or positive.
A mechanism that detects that a visitor to your web page (a sales letter, opt-in page, etc.) is about to act (leave your website as an example), and pops up an overlay on the page that asks them to give a short input to different sections on the page (different influence techniques). You explain that it would help you to better provide what you are offering (you can provide an incentive.) The object of this is to get them to tell you their self-talk – what they are saying to themselves – so you can see if it’s negative, and use that to improve your on-page influence techniques. They can see the original page and new boxes under each section where they can write what they think.