All selling is a bottom-up approach.

Unlike most professions, selling is chaotic. The ability to make a sale is dependent on people's behavior which is largely unpredictable. This inability to predict the perfect conditions that would result to behavior that leads to success, leaves room for a lot of trial and error.

Most professions have a ready script for what works which they follow for success. A physician, for instance, may know what prescriptions work for certain diseases and is at the liberty to replicate those prescription for all cases that seem similar without the fear of failure. A civil engineer too has this liberty. They know what quantities of material should go into certain scales of projects. They can replicate their success without trial and error.

Where success is dependent on influencing people's behavior, there is a lot at play. For example: individualism, mood variability and ability of the individual to respond appropriately. These are but a few variables that determine success or failure of the salesperson. All these variables are outside their control.

Salespeople may come up with scripts and message structures that motivate and nudge prospects to move in the desired direction, but these fail as often as they succeed.

This motivating and nudging people that you believe have the ability to buy is chaotic. This is because it has to be tailored each time for individuals' needs and their current mood. It also has to be done fast via quick qualifying cues. The process cannot be generalized. It is never a one shoe fits all kind of approach.

It is like building scaffolds each time to help you build upwards as you simultaneously build your structure upwards.

A company may come up with a very innovative product that is rationally priced and project massive sales in the boardroom.

This is a top-down approach. From the aerial view, everything seems to have been considered and nothing can go wrong. To compound the company's confidence, the company's sales experts may come up with a very good script for selling the product. This is another top-down approach. The script is believed to have addressed all possible concerns and scenarios.

When the salesperson goes to the market equipped with the best product and the best way to sell it, they are shocked at the discrepancy between the actual and the expected outcome. What was supposed to be an effective script proves to be very ineffective. What was supposed to be the best product receives resistance that is heartbreaking.

This is when the salesperson discovers the need to improvise. They learn the need for trial and error. They invent and test selling methods and learn that the selling methods work differently on different categories of people.

They answer questions about their product and receive insights about what the customer expects.

They accidentally learn things that hadn't been factored into product design and development in the boardroom.

The salesperson is shocked to learn that they are playing a bottom-up game and not the top-down game they had been led to believe.