I have worked and work for competitors of Tobii. The article is kind of biased. The cheapest eyetracker in the world is The Eye Tribe tracker ( I have worked there). They've not been able to solve the battery drain problem yet (running IR LEDs costs you) and therefore mobile gaming is out. I would assume Tobii has had similar issues. Tobii's EyeX is the only Tobii device cheap enough to go into the consumer market but it cannot do a high resolution head pose estimation at a high frame rate. The other awesome company for eyetracking in Sweden is Smart Eye which is targeting a different industry still has issues with high precision at low frame rates. In short, eye tracking is important and progressing fast but we aren't where we want to be in terms of using less power and also kind of supplanting the hand controlled devices for typical use cases like aiming in FPS games or changing POV based on head pose. We've used Tobii as part of competition research and the EyeX API is a bit limited also. I would give this article a 7/10.

Edited for clarity.