Emails receive a reply. I don't call if I can help it. I've marketed myself so that my prices and level of work are clearly noted on my site. I tend to get more tire kickers from calls than emails. I just quickly looked back at the last 10 new client inquiries via email and every one of them pulled the trigger. I didn't stop at 10 because 11th didn't....just didn't look.
My clients tend to be very busy types, who's time is expensive. In my opinion, my clients as well as myself enjoy the freedom setting up appointments via email offers. Monday I go out of town on a $3,000+ job and I have never spoke with the guy on the phone(yes, contract is in place). I will speak with a client on the phone if they like and never scoff at it. But I don't go out of my way to talk on the phone unless it really is something that we need to discuss person to person.