Just don't get it

Surfing on Google News Beta (btw,how long is this gonna be Beta?) this morning, I saw several articles saying this:

Bloomsbury, the publisher which was transformed by Harry Potter, is poised to launch its biggest ever advertising campaign to coincide with the launch of Harry Potter and the Half Blood prince.

ooookay, more than 1 million pre-orders of this book have been made on amazon.com world-wide, it's probably going to be the best selling novel of all time before month's end (that's July, not June, because that's now). WHY do they need to advertise this? I just don't get it. If you care at all about this, you know. You've probably known since the publication date was set last year--whether you want to or not. Why spend the money on advertising?

Ditto for Revenge of the Sith earlier this year. I mean, Hel-lo, we know! Well, okay, a good part of that advertising was to convince the jilted fan-boys that their hopes weren't going to be shattered for the 3rd time in this prequel series.

BTW, in case anyone wants to know, as I hit "Publish Post" there are 15 days, 13 hours, 40 minutes and 32 seconds 'til the release of Harry Potter and the Half-Blood Prince