The same answer applies to your product.
However, I need a way to cut it between people just using the free product and people actually supporting the project, so provide as paying feature something that the big company will require it seemed to me the only way to go.
Unfortunately, I don't have the capital nor the bandwidth to go with fully open source product and selling just support, which I don't believe is anyway a good business model.
If you were in my shoes, you would do something different?
Assuming nosql is for something very efficient or very scalable, I need some space to use it before I have to shell $$. There are many products where I have to pay before going on production.
If I were building a fast prototype I would not use a postgres box anymore but just a redis one.
If you need to cache data in a way more complex than just key->value you don't have too many alternatives at the moment.
If you want an easy and fast way to have an SQL engine in memory, again is not going to be simple.
If you need a separated database for every of your user there are no many alternatives that I am aware of.
It is definitely not a revolutionary product, but it has it's niche, any of the problems that I mentioned can be solved in a different way, but those different ways are quite complex.