I love Pandora... but I hate when they run video ads while I'm on mobile data!
Look, I realize that I'm not "paying" for Pandora, so I shouldn't complain about advertising, but when Pandora chooses to run video ads when I'm not using WiFi, I have good reason to complain. After all, bandwidth isn't free, so it's important to conserve it as much as possible.
Not only does this waste mobile data, but more often than not, when you're not in using Wifi, there's a good chance you're driving, which means it is an unnecessary distraction.