I have tried a couple of known web sites to book a flight from Toronto, Canada to Changchung, China and no matter how many times or days I try - I end up seeing the friendly message below. I mean, do their service have any built-in intelligence at all? I had the same experience half a year earlier so there's something fundamentally wrong going on. Needless to say their customer service does not explain why they fail to deliver the major service they offer - selling flight tickets. Does any one know what is up with that? Thanks

"Due to constantly changing availability, the price for this itinerary has increased. The new price is shown below. If this new price is not acceptable and you would prefer to select another itinerary, click here. We apologize for any inconvenience."


Okay, after visiting the flight center and getting some scary quotes, I came home and tried again the web site that was giving me some trouble in booking my dream trip. Guess what, things changed apparently in the last 2-3 years. If before when I did the search and saw the results and then selected a flight - it meant I could go ahead and book it. Nowadays, the search results just show what you are searching for, but even selecting some flight next second - means nothing. What matters, though, is trying more and more times and then - boom! It goes through and you can complete the transaction. I was sort of excited to hit the jack pot finally. So, yeah, hopefully it helps. Just keep clicking!


This is a frequent occurrence since most results are shown from a cache of previous searches. Routes which include popular flights are booked very quickly which causes the cache to be out-of-date. Even when searching for an unusual flight, one of the segments could be very popular as it might be useful for thousands of routes.

The issue is that the dataset of all possible flight is huge and availability is ever changing as people anywhere in the world can be booking flights while you are searching. There is a cost and latency for actually getting the info directly from the provider, so most online flight search engines show a mix of cached results and only perform the actual search from the back-end when you start the booking process.

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