The secret of great online customer service is speed

When I was tech support engineer many times people were really surprised and thankful for a quick answer.

The trick is to be able to come up with an intelligent answer and not just buying time with the customer. Even though I usually found that it's better to respond fast asking for more info if you don't have the definite answer. The customer usually is happy to have a quick answer but doesn't necessarily get back to you fast. It gives you time to figure it out...

Apologies, empathy, fanatical dedication, and accurate responses which resolve problems are more important than getting to someone within 5 minutes. They're also much easier to actually put into practice for most small businesses.

If you establish and cultivate a perception that you'll be on top of all issues within 5 minutes, then you better enjoy that beeper you just bought yourself, because you're going to be hearing it a lot.

Adjust as appropriate for conditions in your business/industry. (If people can die, spring for the beeper.)