[Baeocystin]

It depends on how much they are willing to pay. For most, they pay enough to get a phone call within the hour during normal business hours, an email response within the day, and a 24-hour window if something happens on-site that requires my physical presence instead of remoting in.

I do have a couple of clients that pay quite a bit more for a call-and-fix any time guarantee, but I only offer that level of service to businesses where 1: there is at least one person on their regular staff who is technically competent enough I can walk through more advanced issues and they will understand how to follow instructions, and 2: I'm the one that built out their network, so I know the gritty details.

For the times when the shit hits the fan in two places at once, I have friends who do similar work, and there are a couple of guys I can call to cover if needed. Obviously they get most of the money from these instances, but the customer stays happy, and I get larger monthly residuals than I could otherwise take care of, so everybody wins.