In the last few decades, we have developed a substantial body of knowledge about CEO succession. However, except for some studies of family businesses that lack direct applicability to nonfamily CEO succession, the past studies of succession have not examined the very first succession event in a firm, when the Founder-CEO is replaced, on a largescale basis. The critical differences between later-stage succession and Founder-CEO succession include the higher level of attachment between Founder-CEOs and the firms they create, the much larger equity holdings of Founder-CEOs (which give them much more control of the firm), the fact that many Founder-CEOs remain in the firm (even though it is being run by their successors), and the fact that nearly all earlystage succession events involve outside successors (in contrast to later-stage succession research, which has focused on the insider-outsider distinction). These differences make it hard to extrapolate from later-stage succession findings to Founder-CEO succession. Therefore, in order to examine Founder-CEO succession, I used field research and grounded theory building to study the factors that should affect Founder-CEO succession in Internet start-ups. I find that there are two central intertemporal events that may affect Founder-CEO succession: The completion of product development and the raising of each round of financing from outside investors. I develop testable hypotheses about how each of these events affect the rate of succession, and then test these hypotheses using an eventhistory analysis of a unique dataset containing the succession histories of 202 Internet firms. My findings point to multiple "paradoxes of success" in which the Founder-CEO's success at achieving critical milestones actually causes the chance of Founder-CEO succession to rise dramatically.