Strange that I have worked with so many designers over so many years that ignore basic research like this. In ecommerce it is a constant battle against block ca

Strange that I have worked with so many designers over so many years that ignore basic research like this. In ecommerce it is a constant battle against block caps for every title, every product name and every banner. It is also a constant battle to get copy in a legible font with sensible line heights. Recently I switched some fonts from the designer fonts to native font stacks with sensible line heights and the conversion rate improved considerably, although I was not able to measure this as there were external factors, e.g. sales promotions, that make this not so clear cut. The consensus is that the faster, easier to read site is winning sales, nobody cares with such emotion about the exact font now it is totally different on all devices, things have gone from being exactly specified to whatever it happens to be on the native font stack, there is almost no way of knowing if that really is 'San Francisco' or not. What I have not explained to my critical colleagues is how the 'SF' font changes from 'text' spacing and font to 'display' spacing and font above 19pt. So the font automagically adjusts itself for optimal legibility and clarity. I think the NASA typography guys would have approved of this approach when designing for displays - use the best fonts on the device. I also think Tim Berners Lee would approve, the original web was supposed to be with the device doing the look and feel.