Steve you don't need to pay for web clicks. Your site is always number one anyway. Most people prefer to click on a search result site rather than a sponsored one anyway.
Totally agree John search result carries much more weight then sponsered listing.
However sponsered listings can help. There are bound to be many search terms that you do not come up top for. Sponsered listings can be a good tool for filling these gaps.
You will amazed at the weired and wonderful search terms used by customers that work if you come up top with them.
"chemdry newcastle"
"carpet shampooer newcastle"
"carpet shampooer hire newcastle"
few examples above. If you ask 10 friends waht they would type in google if they were looking for a carpet cleaner. See how many actually say "Carpet Cleaner Wherever"