... I'll mention Quora here at the blog while I'm thinking about it, because I just answered a question there (that's what Quora is -- people ask questions, and people answer questions).
In addition to asking questions at Quora, you can direct those questions at particular people whom you expect might have good answers. Sometimes I get emails asking me to answer questions because those questions are about something Quora expects me to know about, and sometimes I get emails telling me that some individual wants an answer from me specifically. According to their stats, my answers have received 43,000 views since I started there, which seems to have been in late 2014.
It's pretty fun. Give it a try (no, not a referral link, I don't think there is any such thing, or any financial angle to participating).