I founded a language community in February 2020 as a side project. I did it purely to scratch my own itch - so I could speak German online - so there was no question of charging for it. It started to grow, and my members were using it a lot, so at end of March 2020 I decided to try charging for it.
The deal at the start of April was this: I would start charging all new incoming members, and current members would have until the end of May - two months - to decide if they wanted to buy a membership. At this time they could buy the €10/month membership. By this stage I was knee-deep in bootstrapper philosophy. That is, to charge high and charge early. Always raise your prices, even if it makes you feel uncomfortable. If you offer value to someone, they should pay for it. It is only fair. This was why I decided to charge the current users. Looking back this was a mistake, and I should have grandfathered them in on their free state.
To work through the logic: if the revenue I was to receive from the 100 existing members was so crucial to me, the project was unsustainable. It would not be able to support me and it meant it was not growing. If the project was to be a success, then those 100 existing members would account for a tiny fraction of my future members. The vast majority of revenue would come from members that would join in the coming months and years. In success or failure, there was no point in charging the current members, who had signed up under the impression it would be free. Rewarding them as early members with a free lifetime membership would have been the nobler option. I think it sucked a bit of the collegial atmosphere out of the community.
I have since learned from my mistake, and for my new languages I'm grandfathering in the first cohort.
I wrote a 5,000 word blog post about my journey from being unemployed to being financially independent:
https://constraints.io/my-first-year-building-an-online-community