More salespeople make the mistake of overselling their prospects than underselling. In plain English, they talk their prospect to the point where there is a readiness to buy and then talk them out of that mood, losing the interest and the order after it was there for the taking.
You might account for that by saying that this type of salesperson does not “feel” when the prospect is ready. But that is not a fact. They do feel it, but they figure something like this,
“I’ve got them coming now, but if …