I’m thinking the idea would be to put one at the bottom of the screen and one at the top to collect more data, giving more accurate angles or faster sampling rate. The samplig rate is probably high enough for most cases.
I do think there would be quite a large crowd that would be interested in being able to cut down on that roughly 1 or less than 1cm tracking area on the screen.
It would get it closer to mouse level accuracy for interaction without the need to zoom. Assuming it works.
When different companies start releasing their products a lot of people will be looking for stats and reviews on accuracy of the setup.
I think SMI had their RED-m or RED-n something on the way.
http://www.smivision.com/en/gaze-and-eye-tracking-systems/products/redm.html
http://www.smivision.com/oem-eye-tracking/products/red-n/index.html
It looks very similar, is it the same hardware? Sounds like they are releasing it this summer.
Anyway, I have a feeling that the deciding factor for consumers picking products will be accuracy, reliability ease of use.
Extra features that would allow increased accuracy without zooming in first could be the deciding factor on the consumer market. Anyway, it’s an interesting device that could help free up your hands for other input devices in the future.