I think it's important to think about the future of advertising because it's likely to be with us in some form for as long as there are things to buy. However, I think the author misses the mark a bit on his predictions of the future. I see Pay-Per-Gaze as analogous to the PPM advertising model and I think that there would be a few steps in between PPG and some kind of Pay-Per-Emotion scheme. One reason for this is that the ability to detect other indications of interest is a lot easier than accurately deciphering someone's emotions with just a portable EEG. You could detect if the person mentions the advertising, whether immediately or somewhere down the line, in conversation either in the real or virtual world. Better yet, you could simply create a tracking cookie and then see if they complete some predefined action after seeing your ad (marketers adore PPA). To answer his question, "Is there ever going to be a technological line beyond which advertising won't go?" no I don't think there will be a line beyond which advertising will try to go. However, something as dramatic as reading your thoughts and emotions for advertising purposes one of two things: either so far off that we don't even know the context within which such technology will be received or so close that such a drastic paradigm shift would change the world in ways much more consequential then the easing of advertising.
So this charges the advertisers for each time someone looks at their ad? We are the product, we need to cut out the middle man. We need to create an app that pays the user of the glasses each time they look at an ad. You want access to influence my purchasing habits? It's gonna cost ya.