When I click on the link given in the OP, I see the map but no explanations. So if anyone else has the same difficulty, here's a link to the same map but with explanations attached.

http://strangemaps.wordpress.com/200...p-vs-soda-map/

Since I use the term "soft drink," I checked to find that term on the map. Didn't see it but found a note at the bottom of the page that "soft drink" is the term used in New Zealand and Australia.

Southern New Zealand and southern Australia, no doubt.