If your sales people are committing any of the sins shown below you should take immediate action, as they all reduce your sales capacity and effectiveness.
Talking too much
Epitomised by the catalogue sales person who starts at page one and keeps going until the prospect surrenders or dies of boredom. People talk too much for many reasons, nervousness, excitement or just the desire to show how much (or little) they know. The number one skill in sales is listening. You can’t learn if you don’t listen.
Short termism

Many sales people focus on this week’s or this month’s business. They are often ably abetted by equally short term minded sales managers. Today’s business is important, and I have been guilty of forcing short term business. Sometimes though you can alienate the customer, and indeed lose them later, but you can also miss the bigger picture and better outcome.
Not understanding your customers’ business

It never fails to amaze me the lack of customer knowledge and narrowness of customer contacts that some sales people have. Without knowing an organisation’s risks and possibilities and the people responsible for managing them, how are you going to sell your products and services throughout a customer’s organisation. This is often brought about by short termism, by lack of confidence, by lack of ambition or by all, or a combination of them.
Lack of an inside sales person
All of us need a little help at times; someone who can tell us how our campaign is progressing, what our competitors are up to and what the current internal issues are. An “angel” or inside sales person is a vital part of your armoury and if you don’t have one you are at a distinct disadvantage. However, you don’t just get one you have to work on it by building a relationship that delivers them value at the time you said it would. Simply put you have to earn their trust and respect.

Lack of product/services knowledge

If your people do not fully understand the capabilities of your products and services how are they going to understand what value they can bring to your customers; and when your customer asks that really difficult question or raises an objection, and they always do, how is your sales person going to answer it to their satisfaction?
Poor qualification

Without doubt this is the biggest self imposed waster of sales time and resources and the most deadliest of sins. Why on earth do people work on prospects that will not yield a successful outcome? Much of it is to do with wanting to be seen to be busy but more of it is to do with poor support and sales leadership.
Wasting valuable resources

Have you heard the story about the sales person who has found a prospect, 500 miles from your office who they are sure will take your product if you send your technical specialist to see him or her. Well the prospect doesn’t acquire and what has happened at best. is that you have lost a load of expenses, worse is the loss of one day’s revenue earning capability and worst, the potential of using that person on some business that was real.
Failing to plan

“………… is planning to fail”! It’s old, it’s a cliché, it’s a sound bite, BUT it is oh so true! In sales, planning is required at many stages in the sales process, be it at the outset in Account Planning, or in planning a sales campaign or a call to a prospect. If you do not plan a customer call how do you know it was successful? Yes unplanned calls can and do work, but I am absolutely sure that a planned call with clear objectives and a route to achieve them will always work better.
To finish, just identify what you believe is the most deadly sin in your organisation and remove it.