Research article by Tobias Klinke, Malte Christ, Nader Fadl, Charlotte Lamerz and Tobias Langner published

Abstract
An increasingly common advertising practice uses letter capitalisation in headlines, as confirmed by a content analysis of 700 magazine advertisements (Study 1). However, the effects of letter capitalization in advertising headlines on critical outcomes - including legibility, readability, conveying key attributes, and eliciting connotations - have not been investigated previously. Four experimental studies reveal that in single, short exposures, uppercase letters have two divergent effects on consumers' processing of headlines: The exclusive use of uppercase letters in advertising headlines impedes legibility (reading speed) (Study 2), which impairs readability for long headlines (Study 3), whereas highlighting key product attributes in uppercase can promote direct message conveyance by directing attention toward the key attribute (Study 4). Finally, the authors find no effects of headline capitalisation on indirect message conveyance (connotations) (Study 5) or ad evaluations (Studies 3-5).