Much Ado About Click Fraud?

I just uploaded a post to ChannelAdvisor's blog about click fraud in paid search marketing; what it is, where it comes from, and what to do about it. Here's an excerpt but check out the full post for all the details.

Fraudulent clicks can kill a search engine marketing program. Costs can skyrocket, and for the on-line retailer, revenue goes nowhere. Most of my clients worry about it, and it's tough to impossible to get a complete understanding of the size or scope of the actual problem.