Betting patterns are a form of tell. They may not be as obvious as someone's hands shaking, but if you look for them, you'll probably find a lot more. Of course, you actually have to watch how people play instead of reading forums, doing e-mail, etc. so that you can figure out, for example, the difference between what a person has when they min-raise from middle position versus coming in with a larger raise of 3x or 4x the BB. Or how often they raise as a semi-bluff with a drawing hand. Or many, many other patterns that, once you're aware of them, improve your chances of success.