Problematic business model
Geocities was bought in 1999 for $3.57B and switched off 10 years later. Providing the server and service with no revenue stream apart from paltry advertising, however temporarily popular, could only have been sold for that price if someone making the decision imagined it could become a monopoly capable of being monetized at some point.
Creating a production as opposed to demonstration/research app using such a service is likely to be high risk unless you can know in advance what it's going to cost your users and how they will pay for it. If it becomes a must-have monopoly, your heavy users will be price gouged or have to stop using what they've come to depend upon. If they imagine it will cost nothing it's unsustainable by definition and will eventually be switched off when the investor gives up funding the black hole.