Best keyword or key phrase depends on factors like:

- Amount of traffic and sales leads it will generate.
- Difficulty of attaining and maintaining a top ranking.
- Profitability and conversion rate of a keyword or phrase.

Many site owners choose keywords depending on popularity and based on real life factors. For example, a site owner proposed the term “real estate” due to growth and its generic use. Site would get some visitors but they should also find much better keywords to target with profit and a specific target in mind. Web traffic measurement is done in terms of searches to know how many people search in a day or month for a term. Most popular tools for finding this out is the Keyword Suggestion Tool from Google, Yahoo, Wordtracker, etc. They suggest related keywords, PPC Bids and lists their traffic.

Secondly, even choosing keywords with highest traffic is not enough as these keywords are typically fiercely competitive. Right keyword is one that has a lot of searches but little SEO competition and easy to rank for. Moreover, the focus is fast shifting to actual search from search engines or optimizing for them.

Finally know profitability of a keyword as there are keywords where you may get thousands of visitors with little or no conversion. Although there is no perfect keywords, an SEO and Marketing Expert can help you find the best ones using a combination many related factors.