I help out at Below The Knee on the weekends - it's a family business - and usually sell a lot of running shoes. The way I sell running shoes is to look at the old pair of shoes for tread wear, talk to the person about their running style, mileage, heel strike and so forth, and then ask them what they are interested in. You'd be amazed at how many people are running in the wrong shoes.

I also came across a post at TriFuel.com which mentioned Below The Knee. I'm not sure if I was the salesperson or not, but it's a good story. The link is noted below.