Among my favorites are Quora and Medium. I also see many Quora answers showing up in Google search results for high volume search phrases. There are several great sites like the Penny Hoarder to be a member off. But it always is and always will be about offering value. Personally I think audiences are getting rather annoyed with copy/paste content.
Being a member on these high authority sites like the Penny Hoarder. Is all about building recognition and gaining trust through presentation. That is the purpose of becoming a member. It has absolutely nothing to do with sales!
Which other sites similar to Penny Hoarder are you a member off? And what are your primary goals with such memberships?