Backlinks are a highly important and necessary part of any successful website. Backlinks are essential for Search Engine Optimization (SEO) because they help to judge the popularity and importance of the website based on their backlinks to other sites. That is the main reason there are so many directories online. One well known directory is the Canadian Business Directory. Ca that is well known for accepting Canadian only businesses. You get listed and you get a backlink, simple as that.
Search engines use a number of standard criteria to rate sites on the web and backlinking is high on the list. Backlinks are actually rated by the various search engines by keywords and the content of the backlinked sites.
For example, if your site is about how to cook a hamburger, you would do better by linking to a site about recipes or food preparation than by linking to a site about downhill luging. Why? Because search engines actually cross check the content of not only the link, but the actual sites the link is connecting so they (search engines) can make sure the webmaster is not trying to gain higher SEO by doing things like running several unrelated sites at the same time...