Skill

Contrary to conventional thinking, knowing everything about your product is not essential for success in sales. ("What???")
You’ll never make a prospecting call and get meetings if you believe you need to know it all.
More importantly, focus on becoming skilled at uncovering what part of your product and value your customers care most about.
Do

Your product confidence comes directly from your probing and qualifying skill dexterity.
Today, write down a few questions to ask buyers that will help you understand which parts of your offering they find most appealing.
Try this: "What part of our product most appeals to you?" (Simple, huh?)
Here’s the expert pro move you need to follow up with: ask, "Why?" (And then…listen!)
Alert: ask five different buyers on the same team and you might hear five different answers.
Oomph

Dr. Emmet Brown – played by Christopher Lloyd in this Back to the Future clip – knows everything about his product…the flux capacitor.
Take a two-minute break and watch the moment in the movie when Doc realizes that his invention works!
He’s a great product guy, but odds are Doc would make a terrible seller. Too scattered.
"Knowledge is knowing that a tomato is a fruit. Wisdom is knowing not to put it in a fruit salad." Brian O’Driscoll