Chris Guillebeau and the $100 Startup When building a website, business owners often focus so much on keywords and other on-page search engine optimization factors that they overlook the importance of backlinks.

Some industry experts estimate backlinks may account for as much as 80 percent of the weight that search engine ranking algorithms give websites. When it comes to improving how your business turns up in searches, cultivating links from other websites that point back to your own site is too big an opportunity to pass up.

If you aren't actively building backlinks, here are some basics for getting started:

What are backlinks?
At its most basic, a link is a connection between any two web pages. You might have internal links between different pages on your site or external links that point from your site to other useful web resources. Links that go from another site to yours are called backlinks because they point back to your pages.

Why should you care about link building?
From a search engine optimization perspective, links demonstrate a site's popularity. Essentially, every time a site links to your pages, it's saying that it finds them worthy of sharing with its readers. When search engine spiders find a site with lots of other sites pointing to it, they conclude that the site provides quality information that should be rewarded with high rankings.

There are backlink characteristics that matter in rankings algorithms. For example, a backlink from a high ranked site will count more than one from a low ranked site. A link from a relevant site within your industry also will get more weight.

But since search engines can't manually assess the quality of every site, they rely on the number of backlinks pointing at a site and the relative quality of the links to determine a site's overall value.

Related: What You Need to Know About Brand Building vs. SEO

How can you get started building backlinks to your site?
If you publish engaging content, you probably already get links back to your site. But that's rarely enough to make your site competitive in search results. You should be proactive about developing backlinks.

Keep in mind the following criteria:

  1. Backlinks should come from relevant sites that publish quality content.
  2. They shouldn't be paid for. It's a "black hat" strategy that Google doesn't condone.
  3. Backlinks should be built slowly. If you create them too quickly, you could appear to be manipulating the rankings and trigger penalties from the search engines.

To find sites you might want to target for potential backlinks, first see which websites link to your competitors. You can conduct a search for your competitors' URLs at sites such as MajesticSEO or the Open Site Explorer. Once you discover which sites are linking to your competitors, visit those sites to find out if your content might be a good fit as well.

Related: How Using Microdata Can Improve Your Website SEO

Another way is to track unclaimed link opportunities. Suppose another site has mentioned your site as a reference or quoted one of your articles without providing a proper attribution link. By tracking your brand name and other branded keywords with a Google Alert, you can monitor such lost backlink opportunities and contact the site owners to ask them to link to your pages correctly.

Other backlink opportunities include:

  • Guest posting. Offer to write content for other people's sites. This can help you gain extra exposure and backlinks.
  • Press releases. If you have something newsworthy to share, an online press release can boost your backlink count.
  • Social networking. When you actively participate on social networking sites, you not only brand yourself as an expert, but you also can pick up a number of backlinks.

Although any of these backlink strategies can help your site climb in the search engine rankings, you should track the results to see which techniques have the most impact. Over time, a consistent link-building campaign should yield significant improvements in your search rankings and site traffic.

Related: Five Effective SEO Strategies to Optimize Your Business Blog