HitTail, a gives you in real-time the least utilized, most promising keywords hidden in the long tail of your natural search results, has issued is four millionth writing suggestion yesterday.

This four millionth suggestions, just like all the others, an under-performing keyword phrase that brought someone to a website. If the website owner used that keyword phrase as a writing topic for new content on their site, it will most likely generate additional website traffic through the organic search results.

The HitTail service analyzes the words people have used to find a website through the organic search results. It then creates suggestions for the website owner which can be written about in the future.

As the scale and the scope of the internet grown, it becomes easier for online businesses, bloggers, and other website owners to gain online exposure. According to WIRED Magazine, 9 blogs are created every minute and 2.3 website content updates are posted every second. With an estimated audience of 57 million adults reading blogs (Pew Internet & American Life Project estimate), writers have access to a huge audience on the internet if they have the correct tools to expand their reach.

The HitTail service is a cool service to use for several reasons, including the ability to track traffic from the organic search results in real-time and visually display the Long Tail of search. It also creates high-quality, unique keyword suggestions that can be used as writing topics or keywords for cost-effective PPC campaigns

Since the launch of HitTail in the summer of 2006, the HitTail service has drawn attention and accolades from webmasters, bloggers and marketers for its ability to analyze enormous amounts of data in real-time and generate the keywords that can optimize site content or guide PPC and SEM campaigns.

HitTail is a free service, but also offers HitTail Plus, a premium version with additional features for professionals who manage secure e-Commerce sites or prefer their suggestions by e-mail or RSS feed.

HitTail was named one of the “Best Ideas of 2006″ by the editors of BusinessWeek. It was recently named the best free service for “E-commerce Website Analytics” by PC World.

For more information about your site’s hittail, check out HitTail.com.