Sun, wind, rain, moss growth, hail, snow, etc.If it looks dirty or has green moss growing on the north facing side, it might be worth a cleaning...If the shingles are sliding out of place or look like they are starting to curl on the ends, it might be worth a little maintenance.Outside of that, If no leaks, leave it alone.

We just went through this for a widespread and very severe hail storm in our area back in May. 

For example I have a property with a flat roof that suffered hail damage.

as a hail marry what about owner finance? 

I see you're hailing from Philly, and though I am more a Steeler fan, I have a place in my heart for the city and region.  

In Dallas you get hail and high winds and the insurance tends to be higher.

This is fire/theft and wind/hail coverage.  

High stress, no short term results, and more overheadSending out 1000 in mailing campaign is a very unlikely-to-work hail Mary.

If you've had any hail in the past 4 years, a good inspector will usually find some "damage".

If that roof should have been replaced 3 years ago your not out any money when it hails and destroys the roof.