Its not free in the traditional sense, its just someone else pays for you. These projects work by being "free" with their biggest/most charitable users supporting it. Every major software project that runs the web, be it curl or python, works that way. You do not pay to use the service, you are instead paying to help delay the abandonment of the project and bring updates to improve your experience.

If you don't particually want this project to succeed, then that's fine, though you should probably pay your instance a dollar to cover the bills incurred by your own use of there resources.