I have never heard of this blog. Not once.
The blog is The Blog Herald, as several people at Blogaholics guessed (ultimately, John Evans won the contest, which included a free copy of Blog Marketing).
Why did Duncan sell it? Iâ€™ll let him give the full reasons, but the biggest and best were that he was no longer enjoying writing it as much as he used to, and that there was a perceived conflict of interest with a blog that was in a blog network reporting on blog networks.