Living in the Blurbs

Have you ever selected a book based solely on the blurbs from other authors? I haven't, but I suppose I could have been influenced at one time or another to select a book if some of my favorite authors also liked it.
I read those sound bites on books and wonder what makes an author decide to lend his/her name to a book cover, to laud someone else's work. I know that some must genuinely like the book they are asked to promote, but I am not so much of a Pollyanna that I don't also know how the publishing game works.
So imagine my surprise (and laughter) when a book that had peaked my interest was endorsed by James Patterson. It's a chick lit book called The Irresistible Blueberry Bakeshop & Cafe, by Mary Simses.
Let me just say that this is one time that I should have believed the blurb, rather than the book jacket.
I am not a huge Patterson fan. I know he has a lot of fans (about 200 million of them), and good for you if you're one of them. He just isn't my cup of tea. He also has a fairly large footprint in the crime/thriller category. So what the heck is he doing promoting a chick lit book right on the cover? And in very un-James-Patterson-like terms?
As you know, I like books about food, so I looked past Mr. Patterson and got the book. And it was ... okay. Honestly, it's very James Patterson: all style and not a lot of substance. Again, that's fine for people who like that.
But he should not have compared this book to The Guernsey Literary and Potato Peel Pie Society - a book that had much more substance (and plot) to it. So why should I have believed Patterson's blurb rather than the book jacket?
Because then I would have known that this book would be more Patterson than Helen Fielding and I might have thought twice before reading it. That book jacket pulled me in with the gorgeous blueberries and jam, very little of which is in the book. In fact, based only on the food, this book should have been called The Doughnut Shop.
Oh well, lesson learned in the blurbs.