If your site has no incoming links from other websites, your site will not be included in the Google index. You MUST have at least one incoming link from another website if you are going to show up in Google at all!
Obtaining links from other websites is a time-consuming process. However, without other sites that link to your site, you will likely not rank well on Google for your keywords. More businesses fail to achieve satisfactory rankings in Google because of an insufficient number of quality links than any other reason. Your objective is to obtain the highest number of “high-quality” links as possible from other sites.
Having lots of links is also important for “diversifying” where your traffic comes from – it is not wise to place all your traffic eggs in one Google basket. By growing and maintaining an active link exchange effort, your traffic risk can be decreased.
Link-building also makes you immune to tweaks in search engine algorithms. Links are forever. Each link individually won't drive much traffic to your site, but hundreds of links in the aggregate will over time. Traffic you receive from links on many different sites may eclipse traffic you obtain from Google in the long term.
Off-Page Link Factors Used in the Algorithm
Off-page link factors include that portion of the Google algorithm that determines page importance, which in turn is primarily dependent on PageRank (PR), which is about the quantity and strength of links that point to your site.
The concept of link quality is also an important factor, and is not part of the PageRank calculation. Link quality is determined by keyword factors.
When one page links to another, it “casts a vote” for that page in the form of a PageRank value. The more links you have that point to your site the better, as this increases the PageRank of the page being linked to. The number of links that point to a site is also called it’s link popularity.
Link Quality Factor
Google returns the most relevant results for a given search query. One way Google does so is by analyzing keywords on pages of other websites that link to your site. What other sites “say” about your site on their page is important. This means that the quality of links may be as important as the quantity of links to your site.
You may have hundreds of pages linking to your site, but if the text of those links doesn’t match your keywords, or if the linking page content is not related to your site, those links by themselves may not add any appreciable PageRank boost.
If only the quantity of links to a site were important, every site on the Web would link indiscriminately with every other site and the site with the largest number of incoming links would be #1 for any word. This clearly is not the case.
Specifically, the quality of a link that points to your site is determined by the following:
1. Text of the link – does it contain your keywords? (This very important)
2. Text of other links on the same page – do they also contain, or are similar to, your keywords?
3. Is the link contained in a paragraph on the page, surrounded by related text. Such “inline” links are weighted more than links that are listed on a page without any other text, such as in the footer of a page or a Sponsored Links section.
4. Title of the linking page – does it contain, or is it related to, your keywords?
Linking-Building is About Visitors
The primary value of obtaining incoming links should be to diversify and increase your qualified traffic sources. The secondary value should be to increase PageRank to boost site ranking.
By implementing an effective linking strategy you attract more qualified visitors, you learn more about your industry, you build business relationships, and you become a valued member of the online community. These benefits can bring much long-term reward. As such, link building should be thought more as “business building”.