As someone who has been in the belly of the beast, I'm going to try to summarize the various ways that this article is getting it wrong.
* Most Yahoo Mail ads generate revenue based on impressions, not clicks. So Yahoo isn't directly making more money by grabbing these "random" clicks.
* Where clicks do matter, major ad platforms including Yahoo throw away a LOT of clicks as fraud, and accidental clicks tend to disproportionately get thrown out along with them.
* In general, random clicks are considered a real PITA for major ad networks, as they confuse the heck out of ad optimization. While small players do tend to soak up that revenue, the big players really, really hate the phenomenon because it makes them far less efficient.
* It turns out what most impacts ad effectiveness online is whether people actually see the ad. An incredibly number of ads are just never seen by the audience. As a consequence, a good publisher will try to find locations for their ads that are highly visible. Highly visible and likely to evoke accidental clicks are, unfortunately, highly correlated.
* Most advertisers who are paying per click are very performance driven. They look at ROI, which means they look at conversion rates. When you charge an accidental click, it's almost certainly not going to convert, so in the end you look worse and they pay less for your clicks.
* One unfortunate bit of truth: advertisers do pay too much attention to clicks and CTR (click through rate). Even advertisers doing brand awareness campaigns, which are not looking for immediate response from their audience, tend to look at CTR.
* Yahoo has actually tried hard to establish other metrics that they should look at, like "Bounce Rate", which attempts to factor in whether visitors immediately exit after clicking. They use those metrics internally for optimizing ad performance, so accidental clicks are likely to discourage showing an ad more than encourage it.