Perhaps the best question to ask is:
What is your end goal with your website? What do you want it to ultimately accomplish?
My guess is that few people really think about it, they just put a website up because, well, that's what one should do when they are in business. So, up goes a great website. It's nice looking, it has great pics of your area, it's got your bio, etc.
But...what does it do? You try to get people to visit it, using SEO and your blog and other methods, etc. But...then what happens?
The general goal of a website is to promote your business, right? But it can be SO MUCH MORE than a pretty brochure about your business. It can really work to build your business.
To fully leverage your website and have it be a true business-builder, you need to make sure you can actually capture the info of your visitors. And that does not mean a contact form or your contact info. Very very few visitors will take action with either of those mostly because you haven't given them a compelling reason to contact you.
BUT....if you have a compelling offer and an opt-in box, placed in an obvious spot above the fold, they do have a compelling reason to give you their contact info.
There are loads of benefits, but the top two are:
1. They get great info from you and immediately think of you as a likable trusted expert who they easily might want to do business with.
2. You get their contact info and can continue the "conversation" long after they've left your website!
Compare just those two things to your website now... do you see how adding a simple opt-in form and a compelling offer would seriously ramp up its business building power?
Remember, you want your website to be good business strategy, not just art.