Rand Fishkin from SEOmoz explains how the long tail works and why it is so important to target the long tail in this video below:

SEOmoz Whiteboard Friday – Ignore the Tail at Your Peril! from Scott Willoughby on Vimeo.
The long tail can be applied to both Search Engine Optimization (SEO) and Pay Per Click (PPC) [...]

Hitwise data for January 2009 shows that Google continue their upwards trend to grab most of the searches carried out in the US. Google are now grabbing 72.09% of all searches in the US which is up 9% over the previous year.
Yahoo have lost 15%, MSN have lost 21% and Ask has also lost 21% [...]

It looks like Google may be introducing paid search without using keywords to target clicks in sponsored results on Google. This would be done by way of choosing categories that your business is related to. Read more on Paid Search Without Keywords here.
What effect this will have on Google’s ranking system (quality score) may be [...]

Hal Varian, the Chief Economist at Google explains in a most excellent way, the way that Google AdWords determines ranking factors when you are bidding on keywords.
Hal explains that advertisers want to show relevant ads (most of the time), users want to see relevant ads, and Google wants the best for both advertisers and users.
Hal [...]

Keywords are the essence of Search Engine Optimization (SEO) and Pay Per Click (PPC) marketing. Keywords are what drives the web. When someone is looking for a product or service they usually visit a search engine such as Google or Yahoo and type a few keywords (referred to as a keyword phrase) into the search [...]

Google AdWords is a very advanced and very fair Pay Per Click system. If setup correctly, you can be sure that you are getting the best Return On Investment (ROI) on your Google AdWords Pay Per Click engine due to its Quality Score system.
Quality Score is Google’s way of determining how relevant your ads are [...]

Sure you can. You can open up a starter edition account and be up and running in 15 minutes on your own accord. But…

Do you really know what you are doing? 
Do you know if your account is performing to the best of its ability? 
Are you achieving maximum Return On Investment (ROI)? 
Are you spending your money [...]