A quick disclaimer: this only applies to residents in Southern California and is active through April 28th for the 2017 Spring season.
Fear Rain No More
I understand this desert sometimes has a tendency to throw a mixture of water and dirt at your windows. I don’t want you to pay me to clean your windows and then have them re-dirtied immediately thereafter.
My solution is this: if it does rain and it affects the quality of your window cleaning within 10 days of my service, I will personally come out and make sure all the affected panes are cleaned—absolutely free!