The country you are selling into. Skyscanner runs a separate storefront per country, and they are genuinely different: the same route can be cheapest in November for one country and in September for another, priced in that country's own currency, and some storefronts price a one-way trip where others price the return — every result says which in "priceTripType", so compare that before comparing prices. Every result is also labelled with the market and currency it was actually served in. Two figures — "bookAheadDays" and "airportsServingDestination" — exist only inside the route's written answers and are read in English only, so they are empty on every route on a storefront that answers in another language: Germany, France, Spain, Italy, the Netherlands and Poland always, and any other storefront on a run where it answers for a different country. Each result says which happened in "writtenAnswerFiguresAvailable".
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