Called saying that they replaced my windshield before, and that I should replace my windshield every 6-8 months due to "pitting" regardless of whether or not there are any visible cracks.  They offered $1,000 in gas and grocery coupons.  They couldn't tell me when they did the prior replacement.  I googled the number and it doesn't appear to be associated with any business.  Sounds like a scam, along the lines of:
http://www.insurancejournal.com/news/national/2004/08/10/44850.htm
http://www.insurancefraud.org/windshield_warning.htm