This is true in general terms, but the reality is that these sites are charged to use backend services, so they cache results. So how smart the cache invalidati

This is true in general terms, but the reality is that these sites are charged to use backend services, so they cache results. So how smart the cache invalidation and refresh process is matters a lot to a user, especially during times when there is a lot of contention (think pre-christmas). If there is anything that makes a user bounce, it's telling the user that there exists a ticket for a given price, and the user discovering otherwise after clicking through or starting the payment process. Then there are a lot of providers who have APIs but are not part of a large backend service. Hotels especially are notorious here. Furthermore a lot of providers still don't have APIs (yes, in this day and age) and need to be scraped, and will agree to doing so - the better you scrape the more alternatives your users get. But yeah. In an ideal world what you're saying would be true. And I agree that this is probably a userbase acquisition - market consolidation move rather than a tech one. disclaimer: used to work at kayak.