The primary reason that companies have so many problems between their sales and marketing departments is that top management sees marketing and sales as separate functions. They typically have one VP heading up each of those departments. My view is that Sales is part of, and the most important function, of Marketing.
When I worked for some large electronics companies, I insisted on the position of VP, Marketing and Sales. Thus, I could not blame anyone else if either department did not perform well.
Now, one of the things my company insists on, when we take on a corporate sales training client, is that their marketing people also participate in the sales training. It is extremely important that they understand what the salespeople do and don’t do. Marketing people are required to accept responsibility for increasing sales closing rates by properly qualifying and improving the quality of the leads. They learn how to differentiate between a lead that is of little value and a High Probability Prospect.
Then, we have separate meetings with the marketing people in which they learn how to design marketing programs that are compatible with the company's sales communications. Thereafter, the heads of the marketing and sales departments see to it that both departments are working together, rather than as competitors.