This advert was on regular rotation on the 4 channels available on the telly when I lived in London in the early 90s. Although I was a Tennent's Extra Lager drinker at the time, when I was at another pub, I occasionally ordered a Carling's, on the strength of this ad. And it IS quite a strong ad.
Apparently, the dambusting technique was pioneered by the Brits as part of the Allies' plan to take out Nazi industry. Wonder how successful it all was. In any event, as I've said before, "Love beer. That is all."