I’ve got a little story about big data and airline reservations that I’d like to share with you–about how much the airlines know about you and how it affects you.

I recently wanted to make a reservation from New York to Los Angeles. So I went online at about one in the morning (I do that around that time of day), and I found a fare that I sort of liked for $480.

But I wanted to think about it. So I went back online an hour later, and guess what? It was now $520.

How did the fare go up so much in over just an hour? The airlines will argue that it’s a very popular route between New York and Los Angeles. I’ll take them at their word. So I decided to test out another city pair.

I went back online the following morning, at two in the morning, and I looked for a flight three months later at eleven in the morning, from New York to Des Moines, Iowa. I found a fare of $220. I went back online an hour later, and it was $245.

Now, nobody can make the argument to me that there were 50,000 deranged people who want to go to Des Moines, Iowa three months later on a Wednesday at eleven in the morning and so many, that the fare went up.

The answer is that the airline knew I was interested. Therefore, the fare went up. So what’s the moral of the story?

If you see a fare that you like and you want to hold onto it and go back online an hour later, use someone else’s computer. There’s no proof to this, but my experience does prove the point.