I have one of my websites that seems to be generating 99% of the revenue on my personal site, but I have not really updated it for years since the movie of the book that the site covers was released. The book is also on a school curriculum and is the subject of one of the major exams in one state of the country I live in.
I originally set up the site in 1998 and have carried it across to my own personal site.
I did try and update the site design, but this was disastrous and led to a drop to zero traffic. I believe this was due to site scrapers hitting my site and Google thinking my site was the copy?! I changed it back and traffic returned straight away.
For some reason there was a spike in revenue last year I believe around the time of a major exam that involved the book from the site. To get two payments in six months is quite a shock and it did help me out of a tight spot, before that it took four years for me to get anything (the threshold for payment is quite high.)
As much as I would like the extra money, I just can't bring myself to work on the site as I do not have the energy to do so these days with so much else to do. I was working in content migration/management roles for my actual work but that work has been thin on the ground since the middle of last year.
I spend 99% of my time working on different content that makes 0.01% of the money from the site (Google Adsense does not work well for photos), plus I have had issues with Google Policy Violation where they turned it off on my site as I didn't check my messages for a while.
I don't want to abandon the site, but I am not sure what to do with it going forward. I do still get emails from people asking about the book, but at least no one thinks I am the author of the book these days (the actual author stopped answering emails as it was taking up all his time.)
I'm not sure I understand the situation or what exactly do you look for, but working on something that generates 0.01% of revenue sounds like something that needs a change. We often (it's been discussed) like to work on certain things more than others, and usually..... it's not our higher paying thing, we just love it. Well it comes to priorities :(