People that sell for a living have learned the art of passion.  Most of them were never taught to sell with their passion, but they learned it through trial and error.  The interesting part of passion selling includes the knowledge that you do not have to believe in the product to be passionate about selling the product.  Sales people are motivated by the invigoration of the close.  They are taught from the beginning to ABC or Always Be Closing.  The more you sell the more you learn to articulate, insinuate, and exaggerate at the appropriate moments to increase the opportunity for a closed sale. 

Knowing that people will naturally follow someone with passion, the sales person can take advantage of the appearance of passion for a product, that may really be a passion for selling the product.  When people are passionate their vocal tones change, their facial expressions are different, that seem more believable.  When someone is believable the closing rate will more than double.  The buyers barometer for believability is often their personal interpretation of the passion demonstrated by the sales person.  Great sales people could be considered artist of passion.  They listen carefully to their buyer, they interpret the reactions to comments made, and they adapt quickly to be more convincing. 

Next time you meet a great sales person, engage them in a conversation about something you know they like, and listen to how convincing they are, but be careful, you might find yourself taking a vacation to a location you never knew existed, or investing in a product that you know nothing about, or possibly watching a television show that you had never heard of before you engaged this sales person of passion.  They are passion professionals, and many great businesses rest on their backs.