Underground.
It's safer for me than proselytizing (*), less emotional (people wouldn't appreciate it anyway and it would feel like a wasted effort) and I don't want to pump the price, everyone discovers Bitcoin in their own time and in the meantime I don't mind scooping up those cheap sats.
(*) It's not because I'm afraid my friends might steal from me. They wouldn't, but it takes some knowledge of Bitcoin to know how important opsec and keeping one's mouth shut is. Some of my friends don't even have PIN locks on their phones, if they lose the phone whoever finds it will get access to their instant messengers' chat history etc.