Increasing importance of digital marketing in the business operations raises the need for detailed and data-driven knowledge on the functioning and effectiveness of its various elements. The article analyses one of the most critical components of the user communication process on a landing page – the text or a message provided on a call to action (CTA) button. The research sample covers over 17,000 unique landing pages. The aim of the study was to determine to what extend the semantic type of messages on CTAs together with the length, impact the landing page conversion rate (CR). The results show that shorter and generative messages convert better, as compared to longer tunnel or informative messages. It was also shown that the use of benefit-driven language in communication via CTAs does not translate into increased CR by itself. These findings can serve as a guide for digital marketers who are in charge of designing landing pages, UX writers, and UX designers.