What is custom fitting?

Golf companies are constantly coming out with new equipment each year boasting that they have created technology that will revolutionize the game with increased distance or a bigger sweet spot.
How often have you felt let down by such promises? I know I have. The USGA and the R&A have put limits on club characteristics to ensure our beloved game still requires skill to play. Examples are restrictions on COR of club face (COR stands for Coeficence of Resistance, which just means how much bounce effect a face can have), driver heads and shafts are limited in their size as well as a myriad of other regulations. So when a big name company comes out with something new and amazing they are working within a very limited framework. Adjustable hosels and movable weights have very little effect on ball flight for the average golfer.

Custom fitting does achieve remarkable changes in ball flight, distance and consistency, but the big golf companies need to sell a lot of equipment each year and building custom sets for each golfer is not cost effective for them.