What's interesting about these ads - along with the classic Guinness posters, for example - is that they have become ingrained in our collective consciousness. Call it infinite ad stock if you like, but classics like these are still working today - at least in terms of generating awareness for the brands they advertise, even though the products may have changed beyond all recognition.
And, more recently, I am sure that some of the classic commercials produced in the last century continue to wield their effect through YouTube resurrection. Take this classic from Hugh Hudson. I don't smoke, and Benson & Hedges is a minor brand here in Germany, dwarfed by the ubiquitous Marlboro, but the brand name is still present for me.
The poster of a hundred years ago became the spectacular film of the late 20th Century which became the app of the early 21st century. But I do wonder if something like the Domestos Flush Tracker will still be working for the brand in some way in a hundred years.