Quick, when was the last time you booked a trip through a travel agent? For some of us, it’s been a long time. Others (including myself) have never done it at all. These days we have the internet, and millions of us use one of a handful of websites – Expedia, Priceline, Orbitz, etc. – to book most of our trips.

But what if those sites aren’t always showing us the best deal? Well, it turns out there’s evidence they aren’t. You may already have heard of the cookie trick: if you visit one of these sites and check hotel prices, then come back later from the same computer, the prices appear to have gone up. Clear your browser’s cookies, however, and they go back to the earlier rate. That, it seems, isn’t the only trick up the travel sites’ sleeves. According to a report today in the Wall Street Journal, Orbitz is deciding which hotels to show you based on what kind of computer you’re using. It seems that somewhere along the line, Orbitz users noticed that Mac users tend to spend more on hotels, so they started showing customers who visit their site from Macs more expensive hotels.

According to Orbitz’s data, Mac users tend to spend an average of $20-30 more per night on hotel rooms than PC users, and were as much as 40% more likely to book a 4-star or higher hotel. Of course, Orbitz officials are quick to point out that this isn’t a scam – they don’t show Mac and PC users the same rooms at different prices, they just show them the more expensive rooms first. They also point out that Mac users can still choose to sort rooms by price. They also said that the changes are still in an early, experimental stage, and that they had not rolled out site-wide yet. They also don’t rely solely on the kind of computer you’re using – location and your history with Orbitz count for a lot, as well.

On the surface, then, this practice seems pretty creepy and annoying. After all, why should Orbitz assume I’m willing to spend more money on a hotel just because I have a Mac? How do they know I’m not a broke college student who got the Mac as a gift? The fact that they still allow the same degree of customization, though, alleviates the creepiness a bit. Nevertheless, this sort of search result tailoring is one more example of online businesses using your browsing data in every way they can.