Three places, and the first one is the $55,000.
Market averages for a 2 bed usually reflect listings that are already well run, professionally photographed and priced with a tool. A new listing with no reviews often books below that in its first season, and a tired listing you take over from an owner who was doing it badly starts below it too. If your eight average $42,000 instead, your fee income is $60,000 before you've made a single mistake.
Second, your fee base. Is 18 percent applied to gross booking revenue, to payouts after the platform's host fee, or to nightly revenue with the cleaning fee excluded? Those can differ by 15 percent or more on the same eight properties, and the answer lives in the agreement you sign, not in the market data.
Third, owners leave. Some sell, some move in, some decide to self manage after you've fixed the listing, some get caught by a permit rule. If two of eight turn over in a year, you lose part of that revenue, spend unpaid hours onboarding replacements, and re-photograph a property to relist it. Assume some churn rather than eight steady accounts.
The leak that surprises people is time. Eight listings at nightly turnover is roughly 700 to 900 guest stays a year, each with messages, a cleaning slot, and a chance of something breaking at 11pm. You'll either work most evenings or pay someone for guest communication coverage, and that cost belongs in the model before you decide whether $74,000 is real.