Years ago, we studied the backgrounds of new dealers. At that time, new dealers without prior experience in the industry actually had better numbers. I believe a major reason for the difference is that most techs didn't have prior sales experience. They also had very little experience with customer relationships. I can remember telling new dealers, "At the next stop, make eye contact, tell them 'thank you' even if they don't buy anything."
I was surveying a route for a new dealer in Vancouver, Washington. A shop owner told me, "If your new guy tells me how to fix whatever it is I'm working on, I'll throw him out!" Too often, people without sales or service experience tend to talk about what they do know, which is being a technician. I would always politely explain, "Your job now is to sell tools, not repair cars."
Most of my customers were happy to help me learn about the specialty tools I was selling. You'd also hear things like, "That tool is for [doing a specific activity], but it doesn't work for that application." Then, "We did find out it works really well for a different application."