IIRC the Intel Inside sticker got OEMs a better price on the CPU. Apple probably agreed to pay the higher price and not have their sleek hardware cases sullied by the presence of a (gasp) sticker.
Or perhaps there was enough incentive for Intel to get rid of the last remaining PowerPC platform in end-user computing. Certainly in volume alone Apple doesn't represent a very significant supplier of Intel-based computers.
Apple has more market power than you think -- they focus on a few models, those models sell like hot cakes and Apple pays for guarantees to get inventory. For Intel that means their factories keep pumping out chips like clockwork and inventory is low.
Dell or HP sells more units, but in 300 or more SKUs each. Apple is different enough to get better terms.
This. Intel does not make money from the CPU in the broader sense, they make money by running their production lines at full tilt and getting paid for what comes off them.
Or perhaps there was enough incentive for Intel to get rid of the last remaining PowerPC platform in end-user computing. Certainly in volume alone Apple doesn't represent a very significant supplier of Intel-based computers.