One of the criteria that search engines look at when
determining the page ranking for a site is the number of outside links that
lead back to the site. Depending on the amount and quality of these links, they
can raise or lower a web page's rankings on the search index. For example, If
you've got a lot of trusted links going to your site, then your content is
considered trustworthy and deserves a higher rank on the search engine's
results. The problem with that is you can't build these links on your own – or
you could but it would be too slow. Here are some of the tactics that a professional SEO firm would do
full-time to increase the links back to your site: