I think the whole song fits in with a lot of Pop's themes of consumerism etc, and really just how society is getting shallower and shallower. I mean, what defines people now? What you do, or how much you earn doing it? What type of person are you? Is that decided by your personality, your beliefs etc or is it decided by how you dress, what type of 'style' and therefore grouping you fit into? The labels etc, the need to have the latest and best...
So thats one of the themes of the album (and the title and the tour) and I think where Discotheque fits into that is how that shallow society, shallow culture is affecting peoples love lives and search for each other. So, it's the shallowness of "looking for a night of love in a nightclub" basically. A place where all of those things; looks, dress, income/status factor very highly in that decision making. So, that obviously is completely shallow.
The person in the song knows they are doing this though. Smart enough to be aware of it, but resigned to doing it anyway, and thats where I think the bubblegum line comes in. You know what you are doing, you know what's wrong with it, but you'll do it anyway. Same with the lines "You take what you can get/Cause it's all that you can find/but you know there's something more."
I think there is room in there for a bit of double meaning in relation to drugs, particularly ecstacy, seeing as it truly is the "lovie dovie stuff" and it fits right in with that shallow/pick up idea. I mean, you go out to find love, and you find it by taking a drug. It's a pretty good reflection of what the song is about. I don't think it's just a 'drug song' though.
I'll be honest, in a past life I had ecstacy a few times, and know the feelings and the things that go on and the whole scene, and the words of Discotheque (along with Mysterious Ways for some reason) were often ringing in my head later on.