Effective targeting starts with segmentation: demographic data (age, income, location), psychographic data (values, interests, lifestyle), and behavioral data (past purchases, browsing activity) together describe who a customer actually is, not just who you assume they are. A buyer persona translates this research into a single profile -- a name, goals, frustrations, and preferred channels -- that keeps a team aligned on who they are writing, designing, and bidding for. Personas should be built from real inputs such as customer interviews, support tickets, and site analytics rather than guesswork, since a persona based on assumptions can send an entire campaign in the wrong direction. In markets like Nigeria or Kenya, mobile-first behavior, data cost sensitivity, and strong reliance on platforms like WhatsApp for business communication are often decisive segmentation factors that a generic Western template would miss.