What is Keyword Difficulty?
Keyword difficulty is a measure of the effort required to put a web page on the first page of Google for the desired key word or phrase.
The degree of difficulty will vary from word or phrase as well as for the same term across markets depending on it's popularity in that market and the level of competition. For example trying to rank for the term "golf balls" will be more difficult in the UK market (google.co.uk) then it is in the Indian market (google.co.in)
Factors Affecting Keyword Difficulty
The keyword difficulty varies from market to market as explained earlier. Firstly a market is selected and an analysis of the top 10 rankings (First Page results) is done. To get in the first page we have to replace one of the existing top 10 results on the front page.
There are several factors that affect the degree of difficulty. They are on site and off site factors. Among the important on site factors are the title and the H1 tags of the pages that are currently in the first page of rankings. Another factor is the age of domain. The important off site factors are page rank and back links for the page. There are also several other factors which affect the rankings and all these are taken into account and an average calculated.
Other Reliable Indicators of Keyword Importance
The Keyword Tool from Google displays the number of searches worldwide as well as in the selected market, the advertiser competition and the average cost per click for that keyword or phrase.
Another indication is whether advertisements are displayed along side the search results or not.
Keyword Difficulty Calculations Using Popular Tools
The first example is of the term Golf Balls in the UK market using Traffic Travis 
The example below is of Goa Sightseeing in the Indian market using Traffic Travis
And finally using the Seo Chat online keyword difficulty tool the last example is of Search Engine Optimization in the US market
Selecting Keywords To Optimize
For a new site or a website with low page rank the keywords to be targeted initially are those which are not very difficult and are phrases that contain the words with a high volume of search. For example if you want to target cricket balls in the long term initially target red cricket balls and white cricket balls.
And do not forget long tail words. After all they bring 70% to 80% of all traffic to a website.
