SEO (Search Engine Optimization)
SEO stands for Search Engine Optimization. SEO has to do with tweaking your web site - mainly the content itself - in order to get more optimum results from search engines.
While SEO isn't technically a marketing strategy, the results from SEO help drive more traffic by putting you in more targeted and relevant search results, and hopefully also putting you as close to the top of search engine results as possible.
How SEO Works
Back in the early days of the world wide web, search engines relied on keywords to find web sites relevant to any given search query. The key words were self-declared by the web designer in meta tags within the HTML code. An issue became quickly apparent when certain web sites - namely pornographic ones - began using key words which were completely irrelevant to their site. That was back when doing a search for anything, such as "song lyrics", would bring up nothing but pornographic web sites.
Enter Google, and things began to change. Google began using algorithms in their search engine which basically ignored the meta tag key words altogether, and instead looked at the content of the site. This made it so that almost exclusively relevant content came up in each search query's results.
Search engines today are still not perfect, but SEO techniques are a huge step up from meta tag key words. Relevancy is the key, and search engines work very hard to figure out what search terms might be relevant to your site.
SEO-Friendly Domains
One thing that boosts your SEO is having a relevant key word in your domain name. If your web site is about pine tree air fresheners, having the words "air freshener" in your domain would be a novel idea. Just don't go overboard by jamming more than two or three key words into it and making the domain too long. This isn't the most vital aspect of SEO, but every little bit helps.
SEO-Friendly Titles
Search engines also look at the titles of your pages. Spend some time figuring out a good title for each page, which has relevant key words in it. This is a very important SEO technique, since titles are considered to be something that describes the content of any given web page.
SEO-Friendly Headings
The search engines place a decent amount of importance on the headings throughout your pages. Heading imply that the site is well organized, but they also usually have titles that describe the content a little more in depth than the title of the page itself. For SEO, you want to make sure you use relevant keywords in your headings, and have a good number of headings every few paragraphs or so.
SEO-Friendly Links
Search engines use "crawlers" or "spiders" to crawl the internet and index web pages. When they are crawling your site, they will crawl every single link on it. The names of each link are taken into account by the spiders as they decide where to rank you in terms of relevancy. Rather than having a link called "click here", you would want to use a few keywords to describe the page you are linking to. So a web page about dog breeds could have a link called "dog breeds". This boosts the SEO and is more user-friendly, anyway.
Using image maps or images as links is a big no-no when it comes to SEO. The search engine spiders cannot "see" the picture, so they don't know what the link is about. Many find it unnerving that all their links must be plain-text words for it to be SEO-friendly, but some times one must sacrifice the flare of a web site for a better page rank on search engines.
SEO-Friendly Content
The entire contents of a web page are also used to determine SEO rank. The term "keyword rich" is used constantly when people are trying to get content for their site.
Make sure you use keywords relevant to your site as often as possible without sounding too much like a broken record. Use synonyms for keywords, also, but your targeted key words should be used most often.
The first line of any page should use your target key words, as the first line is considered important when it comes to SEO ranking.
Search engine spiders also take note of words/terms that are in boldface or italics. They assume these words warrant some extra attention. Don't go overboard with this, either, though.
Type the URL of one of your web pages into the tool below to see how the keyword density is on your site:
SEO From Other Sites (Backlinks)
Search engine spiders take note of how many other web sites link to your own. The more web sites linking to you the more relevant they assume your site is. It also takes into account the name of the links to your site, so if possible, make sure that web sites linking to you are using decent names, preferably key word rich ones.
Trading links with other sites is one way to get your link on other web sites. You can also link to it from blogs, articles you write for other web sites, link to it in your signature when you post on forums, on your social networking site profiles, etc. Get creative! Just don't use link farms, as they will actually damage your SEO.