I like the discussion here about an article finding that font choice influences how likely someone is to act on material they are reading. It is pointed out in the comments that the appropriate interpretation is not that Arial is the best font, but that cutesy fonts that get used to add interest or make documents look more “friendly” may actually be reducing the impact of the document. I have seen studies about reading comprehension based on font choice, but this is the first I have seen that talks about how likely a person is to take a particular action based on the font used in the document encouraging them to take that action (here, to go exercise).