Hi Scott, I'm not a warranty guy, I rarely take anything back I purchase, unless it's right out of the box junk.
I worked for Sears about 20 years ago and the salesmen were big on "MA's"
They were a big part of the sale for some of the guys, so selling an "MA" probably isn't a bad idea as far as that goes.
But with that being said, I shouldn't discuss warranty ideas, seeing how my opinion on warranting our services is what it is.
I suppose the difference is maybe the "competition" factor,...having to offer more talk than the other guy to get the work,...fully knowing most customers aren't going to call you back over spider crap under the porch light every week. I haven't any competition to speak of,..so maybe my views are based simply because I don't have to sweeten' my deal so the customer picks me.
As you fellas' say, you never have a call back on warranties,...well for me I've never had a customer refuse because I don't offer a warranty. I've had a few ask, but when I explain what their proximity to infested roofs and the infectious nature of the disease, and nature in general,... they fully understand. But they also like my years of experience and I can truthfully tell them what to expect out of their cleaning. This is also where it's nice to have "landmark" properties to refer them to and say,.."that was done 3 years ago",...or names and numbers from 3 years ago customers.
The real advantage anyone can have is several years of quality work,...no warranty needed!!
Jeff