I think theres possibly a subtext to the ‘share’ campaign apart from the voguish ‘sharing’ is like ‘liking’ social networky thing.
A few years back some of the big confectionary companies got called before parliament over the selling of super-sized chocolate bars – Mars Kingsize and the like. In that hearing cadburys managed to wriggle off the hook because their bars break into chunks and were therefore, they said, something to be shared amongst several people, not one big portion of diabetes for one person. Following that Mars re-packaged their monster sized bars as ‘Duos’ – two small bars in a pack the same size as the previous king size ones. So a pack therefore contained two small portions for two people to share rather than one big one.
The coke share campaign is on the 500ml bottles which are pretty much the default choice in most outlets now, its getting quite difficult to find a 330ml can in many shops except maybe in multipacks. But on the back of these bottles is nutritional info, RDAs etc relating to a 250ml portion, not the the 500ml thats in the bottle.