The Irony of Pay-Per-Click

If you do a search in Google for a variety of retail companies, such as Circuit City, AT&T, Office Depot, etc, there is something very strange happening. Obviously, each search comes up with the respective company in the first few results, but strangely, each also uses a pay-per-click advertisement. This is what I do not understand, if you are already coming up first place in Google and if someone is searching directly for you, why run the risk of spending thousands of dollars on the advertisement? It makes me wonder how many people click those ads and charge these companies money that they never needed to spend in the first place.

The same applies to other companies that come up for more generic terms but still use pay-per-click advertising. Why bother? You have a much better chance of a user finding your website through organic searches than advertising, not to mention organic search engine results are absolutely free.