With projects like this, we’ll no doubt be seeing plenty of critical or dissenting reviews. It appears that Penguin would rather bribe you with books, so that you can write about the books on their blog, rather than your blog. What makes this any different than a horde of Coca-Cola executives standing around watching you every time that you drink a soda?
HarperCollins and LibraryThing have similar programs, but at least you get to pick the book.