Intuition is the answer.
Because Sal is in the landscaping industry for more than 40 years, he has enough of the experience to have an intuition about the decision in his business. There is no need to think hard for the decision, if you have a gut feeling about the things that need a decision.
So on the basis of his experience in this business, Sal has a gut feeling of going with the suggestion of his partner to add the snow removal activity in their business. As he is relying on his intuition, so there is no need to think over and over again about it. Just go with the inner feeling.