I guess it follows that someone in an unpaid position for a profitable enterprise could potentially (perhaps justifiably) not consider clients, clients.If you want to lose a client, that is the exact phrase to use.
Actually, are we the members, the clients? Or are the clients the people who don't sign up/sign in, and view the adverts? I guess I must admit to volunteering my own time and donating my own resources (knowledge, sometimes) to the for-profit gig. So then me & the mods are on the same team, further diluting the "client" role.
</devil's advocate>