I agree with Zelphyr's statement and would add that Facebook should also be avoided for support for exactly the same reasons.
As long as there’s responsive support via standard ‘open’ channels such as email or phone, why would you care whether others can use other channels (e.g. regular mail, fax, or home visits :-) ) to get support?
‘Friendly’ how? I’m wondering how it’s better than a ticketing system or email.