Its a two way street if you have older well worn lifts pm service at calender base will help to keep it going.Oil leaks ect. if it runs out of oil you wont ever need it serviced.Other hand I check about 30 lifts in an hour, half will require service.So customer saves but these lifts are 2004 and are in fair shape.The tech you have will determine if you should stay as normal or change.Ie he help you out by doing repair during pm at pm rate which is cheaper than labor rate.Plugs wire ect not total brake job.Also if you have electric lifts the operators charge the snot out of but never water the battery.If you have a good service man he will let you know if you can extend the service interval.I personaly would rather customer would save on service so he can afford replacement or repair of the lifts he has.