No, nothing to do with Joe Green's opera, but an acronym of a tried and tested model for an advertising message.

AIDA was created back in the 1960s by John Caples, one of the greatest copywriters ever, and was originally devised specifically for Direct Mail copy, then used very much for ALL copywriting and then became an accepted approach to ALL advertising - and I even saw it used for the structure of political speeches.

So what does it all mean? Perhaps it sounds a little over-indulgent, a little too profound? Not at all...

A: ATTENTION. Get the audience's attention. The best advertising in the world is totally worthless if you don't (in which case, of course, it ceases to be the best - and becomes the worst!). That's done the hard work, now what?

I: INTEREST. Hold the attention by creating interest - showing advantages, benefits and qualities. Make the audience 'want' to read, watch or listen further and don't assume that they want to (they were quite happily reading the newspaper or watching a film before you interrupted them!). Their interest span may be very small (a few seconds) so use that hard earned attention well.

D: DESIRE. OK, we've got them listening, we now need to find the trigger that will make them buy, which is called the desire. This is the Achilles Heel emotion that can attract a purchase. Aspirational (it will make me look or feel good). Greed (it will make or save me money). Fear (or 'safety' - something bad will happen if I don't buy it). Sex (it will make me look and/or feel very special).

A: ACTION. Once we've done all this, we must now make the purchase as easy as possible with crystal clear Call to Action details, as well as clearly stating any immediate benefits (why should I buy NOW?). Many a purchase is lost at this last important hurdle. If you make it at all difficult to buy - people won't!

Also, in this increasingly cynical age, we can add a 'C' for 'Credibility' as with the avalanche of advertising we have today, we've "heard it all before!" (but AIDAC isn't quite so much fun, is it?)

I've heard it said that the principles of AIDA can actually over-complicate the issue, and even that it's 'old hat' but I'm quite sure that this is very naive and the necessity for such disciplines are immensely more relevant today than ever before.

There has been a brand explosion beyond imagination since the 1960s and, equally, a media explosion with it with hundreds of TV & radio stations, countless newspaper and magazine titles (my local newsagent looks like the British Library) and, of course, the Internet.

Your product is now a much smaller fish, swimming with thousands of other small fish, in a much bigger pond so the disciplines of AIDA are more important than ever before.