Something that could be interesting to develop for Nostr is a referrals extension for BTCPay or Lnbits.
Referrer is simply your pubkey. Add ?referrer=PUBKEY to the end of a link. Client apps can strip it off if you don’t want them. And upon payment/signup, that pubkey can get credited for the referral. Payment details looked up via Nostr profile.
There is some trust that you are being paid for each and every referral by the service, however, it’s a start anyway.
No need to sign up as a referrer. Leverages lightning. Instant payments. No problems with reverse payments.
I don’t want Nostr to turn into an ad space or marketing shitshow.. however if we can help people become more financially free from governments and a single income, while perhaps replacing marketing/advertising expense with kickback (word of mouth incentive) for a win, win, win, maybe it’s a good thing.