I put the ad removal feature to Simple Budget Planner in the form of in-app purchases.
Even though I seen good number of installs in one week it was not converting. So, I released a new version and started to explicitly ask to the user "Do you want to buy?" after some usage with some frequency. If the answer is yes, I redirected them to the sales page.
I got my first sales after that. 🥳
The lesson here is I guess, explicitly ask your potential customer whatever you want him to do for you. Don't wait for her to find things herself. Explicitly ask.