have you considered adding a free tier? Our project has one and we have had success upselling existing free customers a lot, since our free tier is very limited.

Its different from a free trial since if they like your product will use it until they grow enough to upgrade and might eventually start giving you money.

I can think of countless products that I ended up upgrading from free to paid after using their product > a few months on their free tier.

challenge accepted

Well, how have you fared with this challenge?