Touching some snow….

Friend a few months back tried to get me to buy $XRP … I told him I couldn’t, because it was the devils money. $BTC only!
It’s a pity we couldn’t onboard the Titokers to Nostr…
Is there any way to find out how many ‘active users’ Nostr has had in the last 30/90 days? Like anyone who has interacted with the platform at least once?