I purchased my bike in February, my LBS has the free tune up, after 1000 miles, I brought it back, got the free tune up for the year.
I also purchased two new road bikes, shoes, tires, ect.
Building a relationship is more important to me then $40. I had a tire replaced, free. A flat fixed free. A tire fixed when I threw a spoke (the second time) free, and a guarantee that if it happens again they will replace the rim, free.
My point is, its a business relationship, whats 40 bucks when they know your going to spend money, and you know your going to be taken care of?