Who knows your book better?

Of course, a decent book publicist reads a client's book. Preferably before signing the employment contract...

So, if you, as the author, ask your publicist to pick out the best quotes or excerpts from your book, you might expect a bit of hesitation. Sure, a publicist knows your book, and what the market wants, particularly for matching an excerpt to the publication.

But, really, who knows your book better than you? Why would you want the task of picking the quotes and/or excerpts to go to anyone else but the person who wrote it?