There is a whole lot more to be done than just optimizing your Google Business Listing and calling it a day if you want your local business to rank. You need to optimize your home-page and the main web-pages along with your navigation in order for your website and your Google My Business to be congruent with each other. What you show Google inside of your GMB listing is what you need to show customers on your website. Everything comes down to trust and authority.
