Absolute Mystery

Leafing through the latest edition of The Absolute Sound tonight, I was surprised to see Robert Harley's half-page plug for Jonathan Valin's old out of print mystery novels, apparently now being revived for sale on Amazon's Kindle website. The plug does not appear to be a paid advertisement for Mr Valin's books. Rather, its just another article for the TAS readership to pore over. This strikes me as inappropriate and frankly unprofessional. Am I wrong?