Seems like that on the surface. I'm skeptical if it will be in practice. Content will be on somone's computer and disk space / energy are not free. Also relays can decide what to relay to clients. Nice thing that you can host your own relays though. 

kepford

Nostr feel like free hosting plan but its forever and no limits ,no restriction

AR0w

nostr

nostr as a replacement for a database

0313029d5d

Interesting idea. I'm not knowledgeable enough to talk about Nostr protocol but here are a few thoughts.

* You could host your own relay/s to have more control over preserving data
* Is privacy a concern? 
* Would you need to encrypt the content of the messages?
* I know Nostr has message types. Is there a type that would support this use case?
* How important is performance/latency?
* Is this a solution in search of a problem (ie most "blockchain" projects)

If it were me I'd start by looking at the pros/cons of Nostr as a DB service. Also, it seems like I've see someone discuss doing something like this already. It might have been deploying apps on Nostr. Been a while.