Most of the book criticism they do summarizes to the point where I don’t feel the need to buy anything so I’m not sure it’s personally working as an ad for me.
Some people want the gory details. Every non-fiction book can be summarized as (wo)man v something, but in doing so, you lose the plot. So while you may be satisfied with the summary (and you're not alone!), knowing that it's out there is more important for people to buy than the summarization.