That's his point, setting a cookie on the root "domain.com" will mean it's sent to "www.domain.com" or "blog.domain.com" as well. You mostly do not want this.
However, I was a little tongue-in-cheek there. The RFC disagrees, but browsers have been doing it wrong for as long as I can remember. So, in practice he's right... ;)
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That's his point, setting a cookie on the root "domain.com" will mean it's sent to "www.domain.com" or "blog.domain.com" as well. You mostly do not want this.
Ahem, the text states the opposite of his point.
However, I was a little tongue-in-cheek there. The RFC disagrees, but browsers have been doing it wrong for as long as I can remember. So, in practice he's right... ;)