Link popularity, defined as the number of high quality websites that link to yours, has a major impact on the way your website is ranked by the search engines. Sites with better link popularity will show up higher in the natural search engine results pages which can generate a lot more traffic.

Google's Webmaster Guidelines states,

"Your site's ranking in Google search results is partly based on analysis of those sites that link to you. The quantity, quality, and relevance of links count towards your rating. The sites that link to you can provide context about the subject matter of your site, and can indicate its quality and popularity."

"Google and most other search engines use links to determine reputation. A site's ranking in Google search results is partly based on analysis of those sites that link to it. Link-based analysis is an extremely useful way of measuring a site's value, and has greatly improved the quality of web search. Both the quantity and, more importantly, the quality of links count towards this rating."

( http://www.google.com/support/webmasters/bin/answer.py?answer=66356. See full text of Google's 'Link Schemes' page below.)

Link analysis has been increasing in importance to the search engines, rather than declining. Search engine link analysis gives more weight to links that point to your website from ranked pages as opposed to just the number of inbound links. Search engines are scrutinizing the quality and relevance of links more closely than ever - a trend we can expect will continue as they weed out illicit link schemes, link farms, and pages with no real content.

A high quality link comes from a page that has both high page rank and is contextually related to your page. While a link from a page with a high rank is optimal, a link from any related site with a Google PageRank of 1/10 or higher is considered beneficial in raising popularity.

Search engine link analysis reviews the content on the linking website to determine the quality of the link. Greater consideration is given to links from websites in a similar or related industry where website viewers can be assumed to gain some value from the content on the linking sites.

In the best of all situations, other sites link to you freely because they recommend your information or products. Very large corporations have an advantage over small ones in garnering these gratuitous links. Oftentimes, partners, affiliates and vendors of the corporation will advertise this relationship with a link to the corporate website to increase their stature in the eyes of potential customers. Very large corporations can also increase their link popularity by requiring a one-way link from any company that they work with as a standard part of corporate policy. It is also hard for a small company to compete with a huge one as huge ones have a bigger budget to devote to search engine optimization (SEO).

For the small and mid-size business, link popularity can be increased using off-page SEO techniques for link building. The purpose of off-page SEO is to generate high quality one-way links to your website to increase your page rank in the natural search. As an additional benefit, high quality links will increase traffic to your website and boost sales.

Link building relies on generating superior content about your organization, product, service, and industry. This content can be used in a variety of ways to generate inbound links.

• Build a proprietary Content Network of encyclopedic websites for your products and services to mimic the success of Wikipedia. A Content Network is very useful for sending deep links to build the rank of your inner web pages.
  
  Read more about Content Networks
• Routinely release article and press releases for syndication to have your content included in news feeds and newsletters using a link with your author bio.
• Blog about your products and services and participate in industry forums using a link in your signature.
• Use social network marketing for the viral spread of links.
• While not as content related, submitting your site for inclusion on dmoz.org and other directories also brings legitimate inbound links.

All of these link popularity building techniques will also bring traffic to your site, unlike link farms and reciprocal linking created solely to manipulate rankings.

Link Schemes

http://www.google.com/support/webmasters/bin/answer.py?answer=66356

"Your site's ranking in Google search results is partly based on analysis of those sites that link to you. The quantity, quality, and relevance of links count towards your rating. The sites that link to you can provide context about the subject matter of your site, and can indicate its quality and popularity. However, some webmasters engage in link exchange schemes and build partner pages exclusively for the sake of cross-linking, disregarding the quality of the links, the sources, and the long-term impact it will have on their sites. This is in violation of Google's webmaster guidelines and can negatively impact your site's ranking in search results. Examples of link schemes can include:

• Links intended to manipulate PageRank
• Links to web spammers or bad neighborhoods on the web
• Excessive reciprocal links or excessive link exchanging ("Link to me and I'll link to you.")
• Buying or selling links that pass PageRank

The best way to get other sites to create relevant links to yours is to create unique, relevant content that can quickly gain popularity in the Internet community. The more useful content you have, the greater the chances someone else will find that content valuable to their readers and link to it. Before making any single decision, you should ask yourself the question: Is this going to be beneficial for my page's visitors?

It is not only the number of links you have pointing to your site that matters, but also the quality and relevance of those links. Creating good content pays off: Links are usually editorial votes given by choice, and the buzzing blogger community can be an excellent place to generate interest."

Paid links

"Google and most other search engines use links to determine reputation. A site's ranking in Google search results is partly based on analysis of those sites that link to it. Link-based analysis is an extremely useful way of measuring a site's value, and has greatly improved the quality of web search. Both the quantity and, more importantly, the quality of links count towards this rating.

However, some SEOs and webmasters engage in the practice of buying and selling links that pass PageRank, disregarding the quality of the links, the sources, and the long-term impact it will have on their sites. Buying or selling links that pass PageRank is in violation of Google's webmaster guidelines and can negatively impact a site's ranking in search results.

Not all paid links violate our guidelines. Buying and selling links is a normal part of the economy of the web when done for advertising purposes, and not for manipulation of search results. Links purchased for advertising should be designated as such. This can be done in several ways, such as:

• Adding a rel="nofollow" attribute to the tag
• Redirecting the links to an intermediate page that is blocked from search engines with a robots.txt file