Video advertising is increasingly prevalent, appearing in more and more places across the web and on social media. In many of these contexts ads are typically viewed without sound, possibly impacting their effectiveness and meaning. In this paper we draw on advertising and screen media research, analyze ads drawn from both articles and an agency dataset, and also interview advertising professionals experienced with soundless video in order to build novel understanding of the phenomenon of soundless advertising. Our analysis reveals four strategies and associated operational tactics that advertisers can employ to develop more successful ads for soundless environments. Management Slant • Video ads created for a sound-on environment typically do not perform well when viewed without sound, and subtitles are typically not an effective solution. • In order to be successful in an online environment, video advertising should be designed assuming it will be played soundlessly. • Silence removes an important source of information for viewers and necessitates the use of compensatory strategies to remain effective. • Advertising testing should be conducted with sound both on and off.