You Talk too Much
After 39 years in sales and sales management I have seen far to many sales people clutch defeat out of the jaws of victory! In other words the customer was on the right path to purchase what we were offering but the sales person missed the buying signs. The sales person continued to talk and repeat benefits regardless of whether or not those benefits matched what the customer needed or wanted. The sales person was determined to list out every known benefit of their product regardless of the needs of the customer. While in your sales meeting with the customer be sure to monitor who is doing most of the talking. If it is you then change the direction and ask more questions.
When I first began my career in sales I was rookie of the year in our region for a large tech company. When asked how I had accomplished that my answer was simple "I listened more than I talked"