Best €12 I've spent all year. I found widespread click-fraud on a PPC campaign I was running. The Campaign Monitor was reporting only the bona-fide clicks based on geo-targeting that I'd selected, but they were milking my account of large amounts of small amounts from many more countries that were not authentic clicks and not the geo-targeting I wished. It was only when I started using Apache log viewer that I was able to spot the problem and identify the scale. I contacted the PPC provider and eventually they admitted that my campaign settings had been extended by them! Saved me a lot of time and money. Thanks.