Two things I noticed. Your site can be made more optimized for highly impatient types. I recommend always showing a phone number that leads directly to a sales line with no wait, and a live chat bubble for those too skittish to give you any information.
I always found best results putting the phone number big at the top of the page and again near the contact form. Make it show a special tracked number when users come through ads and the business is open for calls, your regular office number for visitors that didn't come through ads, and a disposable phone number to your cellphone for people that originally came through an ad but tried to call when the business is closed. Make all calls coming through ads go directly to a real person. The justification for all this work is that you already paid good money for anyone that comes through ads so its financially worth a little spam to give them a direct line to a real person. You want your conversion rate as high as possible once you've already paid. If you are a local business use a local area code, 800 # for anything advertised nationally.
For the live chat bubble, make it automatically come up and say something friendly to anyone that has browsed site for more than X minutes or seen more than X pages. Make sure it only shows up when real people are available. Add something near to contact form like "or chat with us now" that automatically opens the bubble and notifies a real person of an incoming request.
In my experience you'll get around 20% of initial contact from calls and maybe 30% from live chat. A decent percentage of these will be people too lazy, paranoid, or old school to fill out your contact form. Email forms are increasingly used for annoying stuff like permission to view the rest of an article, so many users are weary of giving you a direct contact without knowing if their please will go into a black hole. The ability to contact immediately, through phone and especially live chat alleviates these concerns. It makes you real, legit in their minds, immediately.