In reply to SteveF.
There is no true marketing person on earth that thinks eliminating the current market to appeal to a new market is a good idea. It's always done in a completely different manner (as taught in real business schools through the study of cases, over and over).
You enhance your sales by appealing to a new crowd while retaining the old one. If the new crowd becomes dominant then and only then would you add something that might be negative to the existing crowd. This is not always possible. In the case of beer, the market dynamics have changed completely, something you can guarantee AB knows well. Brand loyalty is much less than it used to be. The under 40 crowd treats beer like a wine, trying local brews and different types. Driving off your existing market while trying to appeal* to an under 40 one is not a winning strategy.
*And I doubt the under 40 market responds to the tranny ads any better than the over 40.