GSK's ten nearest neighbors split cleanly between two subcategories: six Healthcare brands and four B2B services firms, with scores compressed into a narrow band from 0.94 to 0.98. Similarity here measures how closely two entities' audiences resemble each other in composition — a score near 1.0 indicates near-identical audience shape.

The Healthcare cluster is the denser half. Novartis leads at 0.98, followed by AstraZeneca (0.98), Amgen (0.96), Pfizer Inc. (0.96), Johnson & Johnson (0.94), and Merck (0.94) — a near-complete roster of large-cap pharmaceutical peers. The B2B cluster sits just behind: Accenture (0.95), IBM (0.95), IBM Data and AI (0.94), and PwC US (0.94). These are professional-services and enterprise-technology firms, not healthcare entities, yet their audience shapes land within a few hundredths of GSK's pharma peers.

The flat distribution means no single neighbor dominates — the gap between first and tenth is just 0.035 — and the cross-kind presence of B2B firms in the top 10 signals that GSK's audience overlaps substantially with the professional and enterprise segment, not only with the pharmaceutical sector.