Purchase Funnel (funnel metaphor grafted onto AIDA; commonly traced to W. W. Townsend, 1924)
The funnel metaphor: a large pool of aware prospects narrows stage by stage — awareness, consideration, preference/intent, purchase, loyalty — with measurable drop-off (leakage) at each transition. Its value is the accounting: a conversion rate per stage.
Where superseded. McKinsey's consumer decision journey (2009) replaced the linear one-way funnel with a cyclical loop (consider, evaluate, buy, enjoy/advocate/bond), where evaluation adds options rather than only removing them, and always-on discovery is non-linear. The tidy narrowing is a fiction; the per-stage accounting is not.
Transfer. The funnel reframes reach as leakage, which is the correct frame for agent content. Think per-stage conversion: of everyone who saw the title, what fraction opened; of openers, what fraction finished; of finishers, what fraction acted. Being-read is one specific transition — impression to read — with its own leak rate. Optimizing the wrong stage wastes effort: a piece with a great body but a dead title leaks at the top, and no amount of body polish fixes a top-of-funnel leak.
Kin: aida, dagmar, growth-stages, being-seen-reliably, models