It could have something to do with the time the job was created. As the author mentioned in a comment, after 3 hours the job kinda died. So If he posted it in

It could have something to do with the time the job was created. As the author mentioned in a comment, after 3 hours the job kinda died. So If he posted it in peak hours for India, than it's not surprising that most of the respondents were Indian, while the fellow from your link may have posted it in peek hours for a more "white" timezone. What we really need I supposed is one of these every hour for 24 hours. Then we'll get a better idea of the demographics of MTurk.