What is the equivalent substitution of cinnamon extract for cinnamon sticks?

According to FreshPoint, Inc., the proper way to substitute a three-inch stick of cinnamon is with 1/8 of a teaspoon of cinnamon extract or 1/2 teaspoon of ground cinnamon to gain similar results.

Much of the "ground cinnamon" sold in the United States is actually cassia spice, which is very similar in taste and aroma to cinnamon. Discern the difference between the two by observing the lighter brown color of true cinnamon as opposed to the deeper reds and browns of ground cassia.

Interestingly, in a study by the Smell & Taste Treatment and Research Foundation, the aroma of cinnamon buns ranked number one as a sexual turn-on for male subjects.