I was curious also so I ran some numbers:

He's the #1 search result for "personal development", which averages 90,500 searches per month from Google. Assuming he receives 60% of those visits, that's 54,300 visits per month. Since it's search traffic, which would be people willing to click and look for info, he might get a CTR of 2%, which is 1,086 clicks per month. The estimated CPC for that term is $1.92, so that is $2,085 per month, or $25,021 per year.

Since that's a rough estimate of $25k/year for one search term, I think $100,000 per year is reasonable.

Your assumptions on this are off. He may be making $100K per year, but definitely not $25K for one search term. Google takes at least 40-50% of the CPC as rev share. Also, the traffic estimator you used is broad match, meaning it includes every query that somehow includes "personal development" such as "Tony Robbins personal development" or "personal development workshop". Many of these Steve will not rank for, even though he is number 1 for the exact match.

I've run a site with similar content and good search rankings that gets around 50% of the traffic of Steve's site (according to Compete), and our AdSense revenue was nowhere close to $100k per year. Even though Steve was using AdSense more aggressively, it makes me wonder how he was able to earn so much. The average earnings per click for us was only 15 cents or so.

Thanks for pointing out my mistakes. I forgot about Google's share of the CPC. Duh. I was also misreading Google's traffic estimator. That exact phrase, "personal development" only receives 14,800 searches per month. Big difference.

A number one ranking on a Google SERP will get you far more than 60% click through. It's usually 90%+. Even if its clearly something different than you were searching for (in the description, etc.) a lot of people just click the first link reflexively. <-- Obviously, that traffic doesn't convert well, but it's interesting.

Quality can be as important as quantity. Slashdot traffic is notoriously bad... people view the content, often using an ad blocker, and then bounce without clicking any ads.

The ones that seem to make money often appear to me as the "high income bloggers that blog about making money by blogging about moneymaking blogs and bloggers and how they made money" type of individuals.

It depends on your readership & your topics.

If you are writing constant posts on personal finances: remortgag, consolidating, getting a financial advisor etc. & the ads that get posted are reasonably relevant (very dependant on the industry) & the readers are 'get a cup o coffee & read' type (digg/stumble/slashdot are reportadly click happy 15 second visitors), then you can get a good amount.

Its important to think about this from the advertisers perspective. The industries where click costs are high are where a large number of clicks can become substantial sales. Services are a biggie: everywhere from mortgage consultants to plumbers.

$1 for 200k views is very little. Typical CPM with adsense is between $1 and $10, so for 200k views you might typically expect between $200 and $2000.

Having said that, Slashdot readers are more likely than average to use ad-blocking software.