Could it be that you used code that referenced seobook.com on purpose?

It would have been just as easy to show off code that works across all generic sites, regardless of their domain name; but by instead using the code that you did, it makes it easier for inexperienced webmasters to accidentally forward their site over to yours.
Of course, I realize you'd never do anything like that. But it makes for a good conspiracy, don't you think? (c;