Randall Munroe’s long-running, well-known webcomic strip xkcd, perhaps best known for this single-panel entry, has released its first book.

They’re not specific about the page count, and it’s not a comprehensive reprint, featuring “selections” from the first 600 comics. The book is $18, plus another $5 for shipping in the US, plus another $10 if you want a signed copy. (But only for the first 24 hours of the listing.) That struck me as a little unusual — I usually see webcomic artists offering signed copies for no additional charge as an incentive to order from them. But if you’re that popular, I guess you can charge extra and impose a time limit.