Link popularity is by far the most important factor for determining your search engine ranking. You need to know what link popularity is, why it is so important, and how Google evaluates it (over 50% of all search engine traffic comes from Google, and if you can rise to the top of Google, you will rise to the top of all the other search engines as well). But, before we talk about how Google measures linking, we need to cover some basics.
Link popularity is defined as the number of sites that are linking to your site. Some websites have thousands or even millions of sites linking to them, while others might have only a few. The search engines use the number of inbound links your site has as a measure of how important your site is, which translates into your search engine ranking.
The actual number of links to your site is not the only variable used to calculate your link popularity. The search engines also examine the relevance of the links to the subject matter of your site. For example, if a website that sells vitamins has 4,000 inbound links, but the source of most of the links are websites that have nothing to do with vitamins, then the algorithm that search engines use to determine link popularity will take that into account, and the link popularity score will not be very good.
It is possible for a website with a relatively small number of quality inbound links to be ranked higher than a site with a bunch of irrelevant or insignificant links. If I have a website that offers quotes for auto insurance, and I have 800 quality inbound links, then I might receive a much higher search engine ranking than another mortgage site that has 3,000 links that stem from link farms or Free For All (FFA) pages.
If you try to acquire inbound by using link farms or FFA pages, not only will it hurt your search engine ranking, but you might get permanently removed from the search engine listings. Links farms are sites where you can instantly exchange links with all the sites listed in that directory. FFA pages are pointless link directories. The search engines usually discount any links that come from either of these sources.
Now that we understand what link popularity is and how it works, we need to look specifically at the method Google uses to measure it. Google uses a number of variables in their algorithm to calculate your overall link score. The higher your score, the higher you will be ranked in the search listings.
One factor that Google uses in their algorithm, obviously, is the total number of sites linking to you. The more links you have, the higher your score will be. However, their algorithm is a little more complicated than that, and it is possible for a website with fewer links to be ranked higher than a website that has more links.
The reason for this is because Google also measures the quality of your links. If your website is about vitamins, and the site linking to you is a video game site, then that is not considered a quality link. The link still helps your score, but the link would help your score much more if it were from a website whose subject matter is the same as yours.
Also, Google gives a higher score to a link if it comes from a page that has actual content that relates to your keywords. For example, if your site is about jewelry, and another jewelry website has posted a link to your site on their links page, that link is not as valuable as a link to your site coming from a blog or a message board where a lot of information about jewelry is being written or discussed.
Also, Google gives an even higher score to a link if it contains anchor text that matches one of the keywords that describes your site. For example, if I have a site that sells lawnmowers, and a blog about lawnmowers has posted a link to my site, it helps my score even more if the link text (also known as anchor text) has the word lawnmowers in it. To learn more about anchor text, go to a search engine and look up anchor text and you will be able to learn about it.
The huge value Google places on having a small number of anchor text links is what makes mastering their algorithm a difficult task. It is possible for a site with a mere 100 total inbound links consisting of mostly anchor text links to receive a higher score than a site with several thousand inbound links.
Another factor used by Google to score your link popularity is the diversity of keywords contained on sites linking to you. For example, if you have a site that sells handbags, and all the links to your site are from other sites that contain nothing but the keyword "handbags," Google considers that to be abnormal. To get a higher score, you need to have links coming from sites that contain a variety of keywords related to handbags, such as "buy handbags," "leather handbags," etc.
It is difficult to increase your link popularity, but now that you understand how your score is calculated, you can devise a plan to improve your score. You might want to consider posting to forums and blogs that contain information that is related to your site, and try to include an anchor text link to rise higher on Google. They are the source of over half of all internet traffic, so if you tailor your strategy towards their search engine, you will do fine.