Being a single male and under 25 makes your rates higher. Being 26+ lowers your insurance rate, and by being married my wife and I are on the same policy so we get a multi-car, multi-driver discount. All the discounts may be small but they do add up.

Oh and I have Liberty Mutual too and they must have changed that rule since I started my policy 4 years ago. I know Geico has the same policy too.