I’m an SEO and it’s extremely important. However service pages and proximity pages are more important. There’s really a million moving parts for local service businesses. Good SEO’s or companies will have a checklist that’s done every month. While blogs are important, what’s the goal of the local service business? To get new customers in your area? or to get more random traffic to your site? If you offer a local service you then you probably want local customers to increase your sales. I wouldn’t focus on a blog then.