The full annual cost of running a booking platform, including subscription fees, per-transaction charges, payment processing rates, onboarding costs, and any add-on module fees. Many operators underestimate TCO by focusing only on the monthly subscription price while overlooking per-booking fees that compound at scale, payment processing spreads above interchange, fees for additional modules like waivers or memberships, and the cost of integrating with other tools. A transparent TCO comparison is essential when evaluating booking platforms, as a lower sticker price can mask significantly higher total costs once transaction volume is factored in.