[patio11]

I'm not him, but I think I can help you on that one. When evaluating the credibility of this, keep in mind that AdWords is not my strongest subject, but I do depend on it for making rent:

Pretend you're a company selling enterprise software. ~$10 will get you a click -- that's right, one click -- for a head keyword in many enterprise-y systems (think, oh, "electronic discovery software"). You try to convert it into an email submission, via offering a whitepaper of some description. Each email is now a lead. Your marketing and sales teams try to sell the leads. The average deal size for successful sales: six figures. Ideally, your best performing sales guys are bringing them in every single month and howling for you to give them more qualified leads.

In those markets, you'd hit over $100k of monthly spend before you eclipsed BCC in AdWords clicks or impressions. (I get mine for about six cents.) You'd probably have a few hundred keywords -- obscure relative to [Justin Bieber], but fairly obvious choices to customers in your problem domain.

You could also hit $250k fairly quickly with a broad campaign as an affiliate aiming to move a consumer product with a high LTV (and hence high CPA). Cell phones, credit cards or other consumer finance, antivirus software (that might be stretching it a bit), etc etc. (On the darker side of the tracks: rebill scams, whatever the latest flavor of fitness snakeoil is, etc.) These guys tend to deal with higher volumes across the keyword tail.