Google Analytics is great, but it wont tell you if they arrived at your website from the direct mail they received, or if it was the grocery store flyer they saw, or the advertisement in the newspaper.
Now you can create an individual link that will direct to your website so you can monitor your marketing activities. Place them individually on your marketing efforts. One for direct mail, one for facebook groups, one for
paid facebook ads, etc, etc. When you sign up for an account, you can track all your efforts exactly.