The key is to understand how and why your products and services are bought and sold, and what business problem your technology solves . Look for patterns that are common to all of the customers that you have interviewed. In short, you want to identify the delineation between generic a sales cycle and where the customized close begins. Marketing supports the sales cycle, the sales force has to do the closing. Review your marketing program and message in light of the information you obtained from the analysis of successful sales.
Marketing is the strategy, sales are the tactics.
Repeat the process every six months. Don't be surprised if your sales analysis both confirms the 'gut feel' you might have had about some issues, but also presents you with some new information that you have to deal with. Identify your last three successful sales that represent your sales goals. Start by selecting the three last successful sales that represent the type of sale that you would like to duplicate. Don't pick all of the same type, but rather a spread of customer size, complexity of application, industries, etc.