In case anyone is interested in pay per click advertising this has been my experience. Only one percent of the people who saw the ad clicked on it and of those that did I won't know how many made a purchase but sales numbers are not up in any significant way. It could be that they would have been worse without the ad, but that is not something I can ever know.
I spent one month's worth of revenue trying to chase more sales that didn't really pan out. I hope others have more luck than I did.