Increasing Qualified Traffic 

The key to successful SEO is to attract qualified visitors. You need the audience that is interested in your website, be it to buy, to be informed, or whatever you wish.

Visitors type in search terms (also known as keyphrases or keyword phrases) when they use Google, Yahoo or Live Search. Searches can be commercial or informational. Commercial searches are likely to end in a buy or sell scenario if the website meets the searcher's needs. Informational searches can range from idle curiosity, to educational research, or preliminary research for a future purchase.

Careful research results in finding keyphrases that are actually being used by searchers. You want to use those that are searched most often. This is important, although in very competitive niches, you may want to go for the "long-tail" or infrequently searched terms if not many other true competitor sites appear to rank for those terms.