From SM&M – The Seven Deadly Sins of Salespeople:
7. Chattering
6. Gourmandizing (never heard this word before)
5. Inactivity
4. Obliviousness
3. Shallowness
2. Presumptuousness
1. Ignorance
You will need to follow the link to read the description of each “sin.” It is well worth the time as the author has laid these out in detail. I agree with all of them though I would have swapped the order of Presumptuousness and Ignorance. My reason is this – a salesperson can effectively close a deal without having a spy (to use the author’s word) within the organization. A salesperson who presumes to know critical pieces of qualifying information will chase many bad deals.
I know this is true because I used to presume. Thankfully, I had a sales manager who would drill me for specific information about a prospective deal before it moved through the forecast funnel. It didn’t take too many visits to his office to understand I needed to gather that information during the qualifying stage of the deal.