When I first saw this in Seattlepi.com, I thought it was rather obvious: the two dirty secrets about blogging are, 1) it's a lot of work, and 2) not many people read your blog.
These are the observations of the author of Random Bytes, which Frank Catalano is shutting down after a year. Frank says about secret #1:
Just because you put a Web log in front of the hundreds of millions of people with Web access worldwide doesn't mean that most, many or even some of them will read it. Hell, they may never know about it.
It's a shame he's closing it down, because he writes some pretty good stuff. It's just part of the large problem of too much information out there to possibly sift through. Whoever comes up with a way to sift the Internet (not search it) will make a fortune. Anyway, here's a couple more observations from Frank:
In most cases, blogging is nothing more than a very public form of self-important self-abuse.
The late Robert Heinlein once observed, through one of his more outspoken science-fiction novel characters, that someone who reads his poetry in public probably has other bad habits, too. Today, that someone would also be a blogger.