I've been using email for my main company, which isn't great. Just finished putting together the new support system, which is still email-based, but also logs everything in a private ticket system and texts if there's an emergency.

Response time: it varies, but it's definitely good to send a "hey we're looking into it" canned response so their issue is acknowledged. It would almost be worth it to have a few of those prepared and auto-reply within 10-20 minutes with one...