Back when I first got hired, and well before my boss clamped down on our tech support policy, I could answer upwards of 20-30 calls a day when school started (I work for a company that makes educational software). Nowadays, I don't answer the phone as much because our policy is if you're not registered, you're not getting support.
Edit: I also don't get nearly as much email either, and my responsibilities have gradually shifted more towards the website design side.