Privacy
What Sky stores
Sky has no accounts and asks for no personal details. It keeps a record of each search as a route, a date and the fare it found, so it can measure whether it is actually finding savings. That record contains nothing that identifies you and is deleted after 90 days.
Sky also caches fares it has looked up, so the same search does not have to be made twice. A cached fare is a price for a route and date, not a record of who searched.
Analytics
Sky uses PostHog to count four things: a search, whether any saving was shown, whether an idea was opened, and whether a booking link was followed. It uses Vercel Analytics for page performance and Sentry for errors. None of them receive personal details, because Sky does not have any.
Booking elsewhere
When you follow a booking link you leave Sky for Aviasales, which has its own privacy policy. Sky passes no information about you to them beyond the route and dates in the link.