Depends on a lot of things. Time of year, economic conditions, location, what other services you provide in addition to mastering and how good a name you have. Bob Ludwig @ Gateway is usually booked up 4 months in advance. I noticed you posted this same question over at the mastering forum on PSW. You seem to dual post a lot. Any reason?

On average, how many gallons of gas does a driver burn to get to work?

How much wood would a wood-chuck chuck?

Seriously, my busy season is usually Oct thru May, so it's several projects per month, usually 2-3 a week, but it's not all we do. Mastering is often provided with the service, as the client generally prefers we do it all for them, from creation through the final pre-replication CD. (We're not a mastering-only facility, as you may have already guessed.)

In the summer, more folks want to catch up and get their dusty old projects wrapped up and completed before the busy season starts again in the fall. So the projects we get from June through late August/early September are anything from transfers and restoration to repackaing old materials to god knows what. Sometimes it's complete sessions as well for release dates in the fall. Most of my "pro" clients are off doing festivals and summer series elsewhere, so it's a nice chance for all of us to catch up and regroup/recharge over the summer.

Come ON, Summer.... 8)