Not only did this guy not get a cofounder, he has never gotten any employees. He's making millions by himself, a total solo effort.
In fact there area lot of examples out there of people doing this... many of them are of the professional blogging/seo/domainer variety. What people on here would deride as "lifestyle businesses" (Personally I don't think you get to deride someone's choices until you've done better than them.)
But further, there's a whole movement of "micro-isvs" - a poor term as it came from someone with a microsoft perspective-- but these are people who make software themselves and sell it. Many of these businesses are on their way to becoming large enterprises. Omni Group is an example of one that's had several years, but Delicious Monster is one that's only been at it a few years- very successful, good number of employees now, single founder. And of course there's scores more.
You know, what we really need is a version of TechCrunch- but one that covers these non-VC backed startups- the companies that won't get coverage in TechCrunch because they are not following the latest fad and burning money on lavish parties to invite Michael Arrington to. For all the little companies you never heard of on TecCrunch there are other little companies who are going to be more successful ... but are under the radar now. I think this is what leads to a distorted perspective of the startup landscape.
I am of the opinion that the ability to quickly make a decision and get everyone behind it is often more important than the decision itself. A "wrong" decision can be corrected if there is a concerted focus while even a "right" decision won't work if founders are hashing out an internal pecking order rather than implementation of said decision.