What is customer segmentation and how do you use personas effectively?

Segmentation divides the market into groups that behave differently and therefore need different treatment. The bases are demographic, geographic, psychographic, and behavioural — with behavioural usually the most predictive, because what people do beats what they are.

For a segment to be useful it must be measurable, substantial enough to be worth serving, reachable through some channel, and genuinely distinct in how it responds. A segment that fails any of these is a description, not a target.

Personas make a segment concrete — a representative profile with goals, pain points, buying criteria, objections, and information sources.

Using them effectively:

• Build them from research, not from a workshop. Customer interviews, sales call analysis, and behavioural data — not assumptions written on a whiteboard.
• Focus on what changes decisions. What problem they are solving, what they compare you against, what would stop them buying, and who else is involved. A persona's fictional name, age, and hobbies are decoration.
• Keep the number small. Three well-understood personas beat eight nobody remembers.
• Make them operational. If nobody references them when writing copy, choosing channels, or prioritising features, they are not working.
• Update them. Markets change and personas decay.

Note: For B2B, distinguish the persona from the buying committee — the user, the economic buyer, and the blocker often need entirely different messages, and marketing that addresses only the user stalls at procurement.