score:4
It was practically instantaneous for my wife and when we applied a year ago. I submitted the online application on 28 January 2013 21:05 and received the approval on 28 January 2013 21:10, and my wife had an identical experience. We were also applying for a 30 day tourist visa.
In case you think nationality might be relevant (it could be): We were both travelling with Irish passports, flying in from Chennai, India.