Local businesses all want to be #1 when it comes to search ranking. And if you search the business name of any local business, chances are it’s going to show up #1, that’s what Google is about. But when you don’t know the name of a business, and you only want know about a certain subject, like house painting, or where to get your cracked windshield repaired, or what a chiropractor really does, Google needs to know a little about the sites that it serves up in results. And the 2 most important factors that drive a search result to be on page 1, rather than page 3, are quality content and back links.
Quality content is generally 3rd party (but not always) information, it’s not not press releases or advertorial, from legitimate sources that offers insight that Google sees as being relevant to the subject. And a back link is nothing more than a website that links to the site that Google is crawling (crawling is the huge set of computers that fetch billions of pages on the web.) They presume that if many sites are linking to a single site, there must be a reason. It shows that the site is credible and provides information that others want to see. Why else would those sites want to link to it?
For more on this, check out SearchEngineLand, 1/20/16.