engine - 10:41 am on Sep 17, 2007 (gmt 0)

Given that most of Google's $13 billion in revenue comes from clicks on ads, you would think the words "click fraud" would inspire fear in Shuman Ghosemajumder, the company's senior product manager and resident click-fraud czar. But the problem--publishers who inflate pay-per-click ad fees with automatic clicking software--doesn't fluster Ghosemajumder or other Googlers. But click-fraud auditors argue that there's a discrepancy: They say you throw away no more than 10% of clicks, while they estimate click fraud rates at as much as 25%.

Google Says Click Fraud Is Overestimated [forbes.com]

Interesting article, and either way we're still talking big numbers.