Recently, I signed up a new partner-member. How did we meet? Via Nextdoor.com
This person asked a question, and I answered them in a private chat.
How did we start talking about Cruises?
In a NextDoor.com email correspondence on a totally different subject, I concluded my email with something like the following:
Have a great day,
I did not say anything else, but that got her interest, she replied and after a few conversations she joined as a Partner/Member.
Try using your signature like this in your emails, and your private chats in Social Media.