Around two million Hammond organs have been manufactured. The organ was originally marketed by the Hammond Organ Company to churches as a lower-cost alternative to the wind-driven pipe organ, or instead of a piano. It quickly became popularwith professional jazz musicians in organ trios, small groups cantered on the Hammond organ. Jazz club owners found that organ trios were cheaper than hiring a big band. Jimmy Smith's use of the Hammond B-3, with its additional harmonic percussion feature,inspired a generation of organ players, and its use became more widespread in the 1960s and 1970s in rhythm and blues, rock, reggae, and progressive rock.
In the 1970s, the Hammond Organ Company abandoned tonewheels and switched to integrated circuits. These organs were less popular, and the company went out of business in 1985.
As evidenced by the attached images, it seems that the only way of selling Organ music was to put a sexy girl on the album cover.