Spin Selling,  written by Neil Rackham probably 30 years ago is the best sales book I have ever read, it has spawned an industry, along with the follow up books.

However, it is not perfect.

In my experience, most businesses of sufficient size to have a purchasing function have a process that drives the progress of a purchase, particularly new items, or those from an alternative supplier.

No matter how well drilled, how empathetic the questioning, how well they seek and find the points where you offering could add value to a customer, falling foul of the purchasing process is most often the end of the line.

The lesson is no matter how well you do your research, ensure you include the mundane details of the potential customers purchasing processes, identifying all the people, understanding the role they play, and identifying the opportunities and circumstances that may lead to “No” and accommodating them in your process.