I've been saying this needs investigating for a long time. From my understanding of things like triggers, priming, threshold for action, etc -- you're probably doing yourself a disservice having out of context advertising.
When you advertise in context, you get constructive interference between the context and your message, leading to a more powerful effect -- your buyer was ready to hear what you wanted to sell; when you advertise out of context, you get destructive interference between the context and your message, leading to muddled or even negative effects -- advertising roast beef on a porn site is probably bad for all three parties! (No matter how much the person viewing porn likes roast beef.)
"Targeted" rather than topic based advertising ignores basic facets of human psychology (eg, that we're very context based animals) in order to pump up ad stock and sell more volume of a diluted product -- because all of the "targeting" is fundamentally a worse replacement for the signal shown by visiting a topical website. It's about inventory fluffing, not efficiency.
That said, the article didn't do the best job supporting that point.