MHes - 10:07 am on Dec 5, 2005 (gmt 0)

Sort of.

Any one phrase will only generate a small amount of the potential relevant traffic. A few sectors will have a limited amount of variations, but it is amazing what words people actually use in their searches. So, lets say you want traffic for "widget hire". The biggest phrase on a keyword tool will be "widget hire" and if you do a site which seo's for this phrase you will see in your logs that "widget hire" is your best phrase. You may be number 1 so you think "...great, 80% of my business is generated by this phrase and the keyword tools confirm that this is the one to chase". The reality may be very different. The searches on Google by joe public during an hour may have been:

"widget hire"
"widget hire in London"
"widget hire with safety harness"
"widget hire for under 21"
"widget hire"
"cheap widget hire"
"holiday widget hire"
"Where can I get widget hire"
"widddddget hire"
"gadget hire"
"small pink gismo hire"
"hiring a widget"

So "widget hire" is the most common, but only 2 out of 12. Because you concentrated your seo on this one phrase, you probably do not rank for the others. Far more effective seo will produce a more balanced page that will rank well for all the phrases. Now lets say you are an adsense publisher. The best bid is for "widget hire" so you manipulate the page so Google shows these bidders on your page. You thus convert the traffic into "widget hire" traffic for the advertisers and get maximum commission. The advertisers try bidding for more obscure phrases, but you don't publish those, hence you continue the myth that "widget hire" is what people search for and the only source of good traffic.