@Banouby I have thought about this advert a lot (/too much). My working hypothesis is that the original line was ‘Thirsty for Worldies’, and got changed because someone in the sign off process said they were worried no one would know what that meant.
@footballfactman Trick question. People got into it so they had something to be passive aggressive about on Twitter, everyone knows that. It's just a freak coincidence that some of it actually seems to work.