Website simplicity in design is a key element of UI (User Interaction). It encourages interface and response, which, when it comes to web forms, is exactly what any business hopes for.
To put it simply, the easier it is to fill out a web form (contact form, request a quote, customer service), the more likely someone will do so.
Having some simple contact information on the page, like your NAP (Name, Address, Phone number), perhaps a Google map widget, can be helpful. At that point, if they want to pick up the phone, let them! Conversely, it is detrimental to ask for a phone number. You may not have yet earned the customer’s trust, and may in turn prevent them from filling the form. If they want you to call them, they can always add their phone number in the message, and you can always ask for it later. They chose to contact you by email, not by phone!
What is the information you absolutely need to get back to a customer?
Ideally, you want/need their name, email address and the message. It is that simple. It is VERY easy for them to fill that out. Conversely, asking for their phone number (which prevents some from filling it out), address, company name, and other personal data that many web-forms require is counter-productive and reduces the amount of submissions.
Speaking of submitting, the word “Submit” has been found to prevent people clicking rather than encouraging them. Studies have shown, in verification of many of these facts, that the word ‘submit’ has such a negative connotation that it alone, when isolated, produces a significant reduction in form completions. Using the form’s purpose instead: Contact us; request a quote; Let’s Go! And so on represent more successful attempts to elicit the response you want: them clicking on the form.
Be Smart about it.
You can often figure out their company name from their email address. You can then get their address, website, and much more information about them instead of slowing them down when they fill the form. They don’t have time for that, and you should take the time if you want the sale/conversion/customer.
Lastly, keep the page itself as simple as the form. This is not the time to distract them with linking back to your site or advertising. They are so close to submitting the form! The contact page should be clean and simple.
To reiterate: The simpler the form (to a point) the more likely they are to fill it out. Which form would you rather fill?