"The Innovator's Dilemma" is a concept introduced by Clayton Christensen that explains why successful companies often fail when faced with disruptive innovations. These companies focus on improving their existing products for their current customers, which can lead them to overlook new technologies or business models that initially seem less profitable or appealing. As a result, smaller, more agile companies can enter the market with innovative solutions that eventually capture the attention of consumers. This shift can leave established firms struggling to adapt, as they are too invested in their traditional practices to embrace change, ultimately leading to their decline.