What does losing the Upper Hand mean?
Losing (or not having the Upper Hand in an interaction) means that your prospect has the social power advantage in the situation at this specific point in time.
What’s the relation between the Upper Hand and the Selling Zone?
Using a sports analogy, let's compare the deal-making process to a tennis match.
Here, the 'Upper Hand' represents points in a game, and the 'Selling Zone' is a game in the match. The person who gets more points eventually wins the game.
The entire sales process is the match, where the seller might be in or out of the Selling Zone during each round.
The outcome of the match is usually defined as either closed won or closed lost.
How do I get the Upper Hand?
Unlike in sports, you're establishing a relationship with your prospect.
To make a successful sale, you have to exhibit the right amount of competence or expertise. By framing the situation and demonstrating your skills & product knowledge, its value is regarded and increases the prospect’s propensity to purchase.
You should display the right amount of competence. Too little, and you're at risk of being perceived as irrelevant. Too much, and you're at risk of being perceived as cocky.
Try to regain the Upper Hand without being too explicit, overt or offensive.