Some people decide to use AdWords just to build traffic only. If you've got the budget, this may not be a bad idea -- especially if you find cheaper keywords to bid on.
However, this is not really the best way to use AdWords because if you aren't tracking anything, how do you know if you're getting any return on your investment?
Larger corporations that can afford to drive traffic this way often do this, but for the average website owner, this is not a great way to start.
Trust me, I've tried it and I did waste a lot of money. It's better to use AdWords with a goal to land a sale for a product or service. That way you have something to track.