Do rave reviews on book covers count as literary criticism?

Dr Ross Wilson discusses the nature of the rave review in The New Statesman and asks whether it counts as criticism.

Getting to put “Booker Prize Winner” and, perhaps, a puff from the panel of judges on your dust-jacket is priceless. But can puffing – the practice of lauding a book’s merits in a few words, usually on its jacket blurb – be considered a kind of literary criticism, however cynically regarded it might be?