If you'd scrolled another 10cm down the page, you would have seen the testimonial from NASA:

> At NASA, RethinkDB is radically simplifying how we provide real-time services in support of Extra-Vehicular Activity. -- Collin Estes, Director of Software Engineering, Chief Architect - MRI Technologies Inc. - NASA / ESOC

My guess is that RethinkDB failed financially because they had a lot of users but not a lot of customers. Most users weren't buying support contracts.