wondering that myself right now. i'd say if you're noticing more noise or distortion than usual then that's a good sign. if you use your turntable quite regularly (say, an average of an LP a day) then replacing it every year or so is probably good for avoiding damage to the vinyl.
there's a bit of a catch 22 involved - damaged records will wear out your needle sooner, and a damaged needle will wear out the records sooner.
― the surface noise (electricsound), Wednesday, 25 February 2004 09:25 (twenty-two years ago)