SEO as a startup growth channel has repeatedly cycled between highly effective and nearly useless, per Casey Winters. It worked well for GrubHub in 2008, for Apartments.com around 2005, and for Pinterest in 2014. It became much harder for startups in the mid-2010s as Google's ranking increasingly favored established incumbent authority over new entrants. It briefly reopened via topical/niche-authority plays, and is now further clouded by AI-generated content flooding search results.
Because of this cycle, Casey's current favorite growth lever is not SEO itself but the pattern behind it: distributing user- or supply-generated content into large external networks that are not yet optimized/saturated by growth marketers — historically this meant Google, but today it means TikTok Search and Instagram Search.
Apply: don't treat 'SEO' as a fixed channel to invest in permanently; instead look for whichever large external discovery surface is currently under-optimized, and treat that as the real, time-limited opportunity — expect it to erode as more operators discover and saturate it.
The specific growth lever: push supply-side or user-generated content into an external network that is larger than your own and has meaningful native search behavior in your category but hasn't yet been fully 'SEO-ified' by competitors. Historically this was Google itself; Casey's current example is TikTok Search and Instagram Search, which now carry significant native search volume in many categories but haven't yet been systematically gamed the way web SEO has. Apply the same content-completeness logic used for web SEO — comprehensive, discovery-optimized content — inside these newer search surfaces before competitors treat them as an SEO channel.