Opinions on recommended service intervals, mileage vs time

[Dealmaker]

My service guy just told me I need a 30k interval service (I have 69k miles), I told the service guy that I thought I just got one 9k miles ago (at 60k on the odometer). We checked the maintenance records and apparently I did the 60k service when I had 57k miles on the odometer back in Sept 2010...2 yrs and 12k miles ago.

So...I'd like to know what the mechanically-savvy here opine. Obviously I drive low miles, mostly stop n go, and commute about 4-5 miles one way daily. Should I be doing my service schedule per the mileage, or per the time intervals? This is a Toyota, not a Ferrari, so I admit to relying on the dependability of the Toyota name to schedule my service intervals by miles and not time.

[Mikestang]

Mileage.

Unless the vehicle sits in a garage unused for like a year or something.