The most important thing to understand about SEO is that building links to a site is extremely important for ranking highly in search engines. The number of links pointing to a site (the link popularity of a site) and the quality of those links (the anchor text used, the page and site the link is on) impact directly on how a site ranks in the search engines.

One great source of links is from blog posts. They have several advantages over traditional sources of links such as directories and text-link ads.

• They are often indexed quickly by the search engines because they love the new content they find in blogs.
• The links appear more ‘natural’ because they are embeded within text and don’t have any of the tell-tale paid link signs (e.g. a list of links under the heading ‘sponsors’).
• If the whole post is about your site, the links are in context and can naturally use keyword-rich anchor text.
• If the whole blog is about the same theme as your site, the link becomes even more powerful.
• Posts first appear on the front page, so a site is initially linked from the the page which gets the most traffic and usually has the highest PageRank.
• Posts are then usually archived into categories, which means it will be on the same page as lots of related content and links.
• Finally, a post usually has it’s own page, where the links to your site will remain forever.

So where do you find blogs willing to review your site? There are brokerage sites that act as middlemen between bloggers and advertisers. A couple of examples include http://www.reviewme.com/ and http://payperpost.com/. You pay a premium for this type of service, but the available blogs are of good quality and will usually provide traffic as well as link popularity. Another advantage (or disadvantage) is that the blog posts are clearly identified as paid reviews.Another source is specialised site review blogs like this one at digitalpoint.com. These are often cheaper than blogs found through a middleman  andsome  allow you to write your own post. Good ones have a number of categories for posts, which keeps them with relevant content once they are off the home page.  PlanetStrange is one that has categories ranging from building and construction to food and drink.

Another approach is to use blog networks. These are groups of blogs , sometimes containing hundreds of sites where a posts are published automatically. Sometimes the post is written by the network owner or can be provided by by the site owner. The problem with blog networks is that they could be considered spam and can contain links to poor quality sites that you would not like to be associated with. There is also the issue of duplicate content. The search engines may identify posts on the network as being duplicates and discount the links from them. Some of the more advanced networks allow you to submit a number of different versions of a post or can automatically generate variations. It is probably better to use these networks or to only use small networks, for example 10 or 20 sites.

Probably the best, but most time consuming method is to search for relevant blogs and directly approach the blogger. It may be neccessary to be more flexible about your requirements, i.e. the number of links to your site, the anchor text used and deadlines, but it could be worth it for a very natural link back from a highly relevant site.