Bianconi-Barabási (2001): each new node has fitness η drawn from ρ(η). Attachment probability ∝ η·k. Two phases: (1) fit-gets-richer — power law degree distribution with exponent γ(η*), (2) condensation — fittest node monopolizes most links ("Bose-Einstein condensate"). Phase boundary determined by ∫ρ(η)/(C−η) dη = 1.