In a world of software, where arbitrary lines can be created between free and pay for functionality, I expect no more or no less than documentation that clearly defines what is included for free and what requires payment. In your goal of marketing your solution you have
1) Failed to do so
2) I believe constructed the feature set with the goal of having users spend enough time with your offering, they would rather spend the money than give up on their lost time.
I find such practices unethical. Your judgement shows a lack of maturity and character. For the record, I’m working on a personal web site, with no intention of collecting revenue (ever). So yes, I’m paying to host a site, publishing information which I hope is of value (including software I’ve written and am providing for free), so please don’t use your personal sense of values as basis to judge others so absolutely.