The founder of modern consumer research was George Gallup who set up the eponymous Gallup in 1935. One of his early studies for advertisers showed that when a consumer is reading a magazine, headlines in BLOCK CAPITALS are read less often than headlines in Title Case. With identical adverts, simply changing the font of the headline would increase readership of the whole advert.
David Ogilvy, one of the founders of modern advertising, makes this point in Ogilvy on Advertising which was published in 1983.
In 1963 Margaret Calvert along with Jock Kinneir were given the task of redesigning British roadsigns to make them easier to read for road safety. Of course part of her work was moving from block capital to title case, in the process becoming the first person to earn an OBE for services to typography.
The Americans finally caught up and in 2010, New York began the $27.5 million process of changing their signs from capitals to lower case for safety.
In short, there was been nearly a century of research that has constantly shown that Title Case is more effective than BLOCK CAPITALS for headlines and this research has been widely covered in the media and in the literature (if you Google you will find many more articles I could have mentioned). Why then do most adverts still use block capitals?
It’s a very good question to which I’m not sure I have a complete answer. I do think a big part of it is that marketing is simply not perceived as being a serious profession. Recently I came across a company where the Chairman’s son had been given a vital marketing role despite having no experience in the subject. It would be hard to imagine this happening in accountancy or law. We really do need similar standards being demanded for marketing as for the other professions.