This paper studies how a representative of one commercial user industry, life insurance, interacted with key players in the newly forming computer industry after World War II but before any computers were sold for commercial purposes. In particular, it shows how Prudential's early computer expert and proselytizer, Edmund Callis Berkeley, viewed computer technology and its potential uses in life insurance, as well as the ways in which he influenced its development. Immediately after the war, Berkeley set out to educate his superiors at Prudential and the life insurance industry as a whole about the potential uses of computers for insurance; at the same time, he communicated that industry's needs, especially in the areas of rapid input-output and verification, to potential computer vendors. His internal efforts culminated in the contract Prudential signed for a Univac computer. Although the contract was ultimately broken, Berkeley's efforts appear to have influenced J. Presper Eckert, Jr., and John Mauchly in their development of the technology. Berkeley's activities in the 1940s reveal that interaction between vendors and representatives of potential commercial users was earlier and more intense than historical accounts of computing generally recognize and that users may exert a powerful influence on the development of technology.