But he doesnt sell much of it. He uses Amsoil gear oil and ATF regularly in cars he services, but does not push the motor oil. Why?

I suggested to him that it was because he would lose money on oil changes.

He says no, not really. He said most people dont pay close enough attention to their cars to safely abide by the longer drain interval. Without regular checks and top-ups as needed, synthetic could be a detriment in the long hall - ie running out of oil. Plus if he only sees the car every 15K or whatever, he cant check large problem areas such as brakes and timing belts.

Interesting, I say.