Yes, but he's already written large parts of the book on his blog. He could outsource an editor or even ghost/cowriter to assemble it. Could be a possible project for after he quits the day job, but there are probably others that would pay better.
This advice is written from the perspective that writing is 100% of the project. Writing is 10% of the project. Writing a salesletter, a marketing site, linkbaits, and obsessive promotion is the other 90% of the project. That is time debt that I take on as soon as I sit down and say "OK, I'm going be become an author."
The upside to it is miniscule: I know I can sell thousands of copies of software for $30, because I've done it, and am reasonably certain that I could sell accounts at a new SAAS for $100 / month, given time to work on it. I am not sanguine about my ability to sell thousands of copies of a book/ebook -- my most loyal blog readers number in the hundreds, if that. I'd also expect massive pushback on the prices that I think make sense -- for examples, take a look at every launch of a non-software info product on HN. (I think I'd be particularly at risk for that because a non-trivial portion of my audience likes the fact that I started a business for $60 -- and when you have $60 in your budget, $X00 on a book is right out.)
There are also psychic costs to me. I kind of value my participation at HN and the Business of Software, for example. It is my sanity-preserving lifeline. I'd really hate to have every post carry the implicit disclaimer "Warning! He is trying to sell you something."
Now, there's absolutely no money in it, but getting published dead-tree can give you a lot of credibility and publicity, and it's not as hard as it once was (see the bit about 'there is no money in it')
As far as I can tell, writing a dead tree is /easier/ than writing a ebook, and distribution is easier, etc... you keep less of the money, but more of the credibility.
