Here is a method that may provide what you need plus some extras you may not have thought of. It is particularly useful because you mentioned you did not want to put code in every topic (like Google Analytics, etc.)
While it costs extra and requires more setting up, the Adobe RoboHelp Server 8 solves a couple of your problems:
Content "Optimization" - Using RoboHelp Server Analytics to improve content.
- It requires no code be written in your topics.
- The end-user does not have to "do" anything such as click a button, send an email or fill out a form (it's passive)
- Feedback Reports (summary. There are actually 7 reports) -
- Usage statistics, how often certain topics are accessed, etc.
- Search Terms Used - You get a list of the verbatim search terms that are entered into the search box (even if misspelled)
- Search Terms that return "No results" - perhaps most valuable, because if an author knows someone is looking for info they can't find, the author can then create content to fill the gap or make the existing content more accessible.
Another benefit of RoboHelp Server 8 is the ability to create "Areas" for different audiences that are password protected. This may or may not be something you need, but it actually turns out to be quite useful.
I am offering a free 1-hour webinar on behalf of Adobe on October 28 that explains this in detail. You can register here:
The main product feature page is here:
Adobe Certified RoboHelp and Captivate Instructor