Benchmark incumbents validate the category: NUET at ~$7/mo (~$70/yr) proves people pay for inbox-to-calendar, before the PDF/newsletter differentiation is even tested. Market banded $500M–$1B total, Year-1 target $100K–350K at ~$70/yr.
The differentiation — "email + PDF + newsletter → my calendar" with caregiver-native positioning — is positioning, not a hard moat (the business case's own C grade). And the named biggest unknown is willingness to pay for a narrow tool vs tolerating chaos; the recommendation was GO on validation, not on a big build.
Stub — edit freely. Sources: docs/business-case.md (Market, Existing Options, Biggest Unknown, Recommendation).