As an affiliate you are marketing someone's brand and receiving commission on revenue created by referrals. Naturally you want to maximize that commission so you can sit on a beach with a cold mojito and watch the waves. To get there though, you need traffic to your website.
Naturally the world of SEO is highly competitive because those who control the traffic make the money. Search Engine Optimization deals with how your website appears in search engine rankings.
The basic element of search engine optimization is the keyword. A keyword or key phrase is what people type into a search engine such as Google, Yahoo etc to try and find a relative site.
Back in the old pre millennium bug scare days there was many search engines vying for market share and you could choose between AltaVista, HotBot, Excite, Dogpile, Infoseek and a whole host of others to run your searches. It didn't matter which site you searched on as most engines used the web databases supplied by a company called Inktomi.
Inktomi traversed the web recording everything it found and stored the data for us to search through and depending on our search terms it would spit some results back at you which was pretty inefficient as you never knew what site you would end up at.
These search databases were advanced for their time, but we quickly learned that Inktomi was simply collecting the basic meta tag info such as the title, description and keywords and then the entire text and html tag content of pages.
The algorithms created by each search service provider was pretty similar too, and would basically weight your page based on its content for the keywords. Each service provider would weight or grade the pages slightly differently giving priority to the title meta tag, or how many times the keyword appeared in the top 50% of the page text. Some would count the image alt tag text and others any text you put inside html comments in the source code of your pages.
This was seen as a very cool and advanced way to map the world wide web content, but as everything technology based it becomes old, redundant and eventually needs updating and this is where issues started to appear.
Quickly the commercial minds of the internet took over and webmasters would "keyword stuff" website pages to drive traffic to their websites. Keyword stuffing is effectively over loading meta tags and pages full of relevant or irrelivant keywords and phrases to drive targeted traffic to their pages.
An example would be a website that appeared to the search engines like it was free pictures of Pamela Anderson, when it was actually a website that sold body building supplements to men. It is the right target audience, but the webmaster built the site to dupe users into thinking they would see lots of nice pictures, but then deliver something completely different.
Alas, search engines had to develop fast as users were becoming frustrated by the unreliability of search results and directories were becoming more favourable. Up to now, search engines licensed the Inktomi database, plugged it into a web search interface and in return for using the search engine you usually got a few ads at the top and tail, but now they had to work harder to give you better quality results or risk losing your business and advertising dollars.
Other than manually visiting each website to check the content, a new algorithm needed to be developed that was a little more intelligent than its predecessor. It is probably at this point where I will no doubt upset a few people, but no matter how complex you think an algorithm can be, it is as good as the data it is fed with and there isn't much you can do other than understand the basic content of a web page, how many people link to it from other websites and how many people visit it.
A search engine spider is a simple creature, and from what can see not much has really changed from the late 1990's. For sure, a global business industry has been developed around mystifying search engine optimization and listings, but the reality is that it's pretty simple and if you stick to some basic rules you will do just fine and see targeted traffic come to your website.
Primary - Your primary keywords should be the main search term you are trying to attract. For example "Affiliate Program". Your primary keyword should appear in your Title meta tag.
Secondary - Your secondary keywords should be the descriptive element to further target your primary search term. For example "Casino". Your secondary keywords should appear in your Description meta tag.
Underlying - Your underlying keywords will further assist the search engines in determining he content of your website. For example. "Gambling, Blackjack, Roulette, Cash" etc. Your underlying keywords should appear in your Keyword meta tag.
Title - The title of your page. It should identify exactly what your page is about bearing in mind that this is also what search engine users will see as part of the search results, so it needs to be clear in its message and include some of your important primary keywords.
Description - Again the description meta tag should have a nice clear more detailed description as parts of it will be displayed for search engine results and include some of your secondary keywords.
Keywords - The keyword meta tag should include all your primary, secondary and underlying keywords.
Once you have constructed the content of your page, use a keyword cloud tool such as Webconfs Keyword Density Checker to give yourself a visual representation of the content of your pages and adjust your page content to fit closer with your Primary, Secondary and Underlying keyword targets.
As a rough guide you will want your primary keywords to be somewhere between 4% to 7% of the page content, secondary from 2% to 4% and a sprinkling of underlying keywords around the 1% to 2% mark. All of these can be finely tuned at a later stage once you have established your competitions keyword page weights.