The number of gallons of jet fuel dispensed at your airport is a good general indicator as to the total size of the market of course, and how active the airport is – the more fuel dispensed at the airport, the more active the airport is, and hopefully this translates into healthy fuel sales volume for your FBO.
You will need to provide a spreadsheet of the Airports annual fuel sales for buyers. Airport’s report annual fuel sales (on a monthly basis) in various ways so caution is the rule. It’s necessary to break down the gallons of jet fuel dispensed at the airport by customer type, such as airline, airline in-to plane, general aviation, military, etc.
Remember, an airport might report 15,000,000 gallons annually dispensed, but when dissected, a buyer will discover that 14,000,000 gallons is in-to plane (to commercial aviation carriers at very low margins). If this is the case at your Airport and FBO, its likely your FBO collects a very low uplift charge per gallon of maybe only $0.015 to $0.10 per gallon of revenue. That’s okay if at the low end of the uplift charge we just mentioned, it applies to many multiple millions of gallons of uplift. But if the uplift gallons are more modest then you hopefully have negotiated collecting, for example, $0.10 per gallon or more (as long as your labor costs and profit are covered) the revenue from uplift fuel services should be positive and add to the value of your FBO for sale.
So what initially may look like a high-volume airport for fuel sales to a buyer of your FBO, which would be very positive to that buyer, in reality the vast majority is in-to plane uplift fuel at very very low margins. Not enough to sustain on its own the profitability of your FBO to be sold, unless there is considerable general aviation-based and itinerant fuel sales at much higher margins.
Part two of the number of gallons of jet fuel dispensed at the airport is what market share does your FBO have? If the total fuel sales occurring at the airport for general aviation are for example reported to be 5 million gallons per year, hopefully the market share for your FBO will be at least 50% of that total or 2.5 million gallons per year. If your FBO has a significantly smaller market share of the total, say 30% of the market or less, the value of your FBO for sale is going to suffer. You will have to look at the very reason for your smaller than approximately equal market share of fuel sales and be able to rationalize the reason for it to a prospective buyer of your FBO. Just be prepared to answer this question should it arise.