It's not like someone at Orbitz sat down, rubbed his/her hands with glee and said with an evil laugh, "ha! I will rip those Mac users off!" In all likelihood,

It's not like someone at Orbitz sat down, rubbed his/her hands with glee and said with an evil laugh, "ha! I will rip those Mac users off!" In all likelihood, someone used the browser type as a feature in their model. It so happens that Mac users are (or were) younger, slightly more financially successful and like to splurge a little (e.g., the Mac itself, when comparable Windows laptops are significantly cheaper). Hence the model learned that it can show more expensive hotels to users with that specific browser type.