If you use your watch in water, say you swim or shower with it, then every 3rd time you need a battery should be about the time Omega can do "preventative maintenance" where all the gaskets should get replaced, seals checked, and sometimes replace the crown if Omega recommends it. They also check for manufacturers defect. In my case, the band clasp was eventually considered a substandard design, so Omega replaced it for free. I never would have known had I not sent it in for a PM. The phosphor on my watch hands started to flake off, and Omega replaced them for free as well.
If the metal finish on the watch get's marred from use, then getting it buffed could at least get most of the light scratches out, and any gunk that builds up in the band and under the bezel.
Otherwise, the watch needs virtually no service unless some dysfunction calls for it, So it really depends on how you uses it in terms of water exposure, and scratches from wear & tear.
If you want to use me as an example, I have a 20 year old Titanium Seamaster Quartz. Every 3 Battery changes 5-6 years, I have everything checked by Omega in Lancaster PA. Every other time 10-12 years, I get the bezel & band buffed, so last year I did it for the second time since buying my watch. Keep in mind that such service is not cheap. Between buffing and gasket changing I've spent over $1,000 on service the past 20 years. But after all this time, my watch works and looks as good as new despite daily wear. So how you service may also depend on how "loyal" you are to your watch. Who knows, I may have been better off spending that grand on another watch...
