Do not compare hotel SEO only with doing nothing. Compare it with the acquisition paths the property is already using, especially when the goal is to move a defensible share of demand toward direct booking.
The source previously used 15% to 25% of gross booking revenue as an OTA commission range. It also illustrated the effect with a $200 nightly rate and a three-night stay, producing $90-$150 in commission. No supporting source URL is present, so these figures should remain historical examples until reconciled with the hotel's actual OTA agreements.
A direct booking does not automatically mean the OTA cost becomes zero in the full acquisition model. The earlier source used a booking-engine fee of 1-3% as an example of transaction cost. Keep that example separate from your own payment, booking-engine, loyalty, paid media, and operating costs when you calculate incremental value.
The same source compared a $3,000 monthly SEO retainer with $0 and then with an illustrative $18,000-$30,000 commission total tied to 100 incremental bookings at an average booking value of $400. That comparison is useful only as a scenario template. Replace each input with property evidence before drawing a financial conclusion.
The decision question is whether measured organic bookings, together with any defensible commission displacement, justify the full SEO investment over the chosen evaluation horizon. Keep average booking value, current OTA dependence, and organic competition as separate variables so one assumption does not hide another.
High ADR or heavy OTA use may make commission displacement more material, while saturated search markets may make organic acquisition harder. Those are considerations for modeling, not guarantees of stronger or weaker return.