The Nostr protocol doesn't inherently support cryptocurrency transactions. It's a protocol for creating a censorship-resistant global network. In the context of Bitcoin, mining refers to the process of validating and recording transactions on the blockchain. Miners solve complex mathematical problems to validate transactions and are rewarded with newly minted bitcoins. When sats are sent via Nostr, the mining process is still being handled by the Bitcoin network, not by Nostr itself. The Nostr protocol merely acts as a medium for initiating or communicating the transaction.

The rationale behind sending small amounts of cryptocurrency to strangers can vary. It might be for tipping content creators, rewarding participation, incentivizing certain behaviors, or simply as a gesture of goodwill.

Solutions like the Lightning Network are being developed to address Bitcoin's scalability issues by enabling off-chain transactions. Integrating such solutions could be a consideration if Nostr were to support cryptocurrency transactions.