Short video excerpts from TV shows are a tool that producers/broadcasters use to promote their programs. This study examines how video highlights that are presented online for free viewing, which can be analogous to product samples for entertainment goods, affect TV audience ratings. We investigate whether a displacement effect exists, i.e., the substitution of goods due to the availability of other similar goods. We find that positive viewer response, measured by the number of likes and views generated for the highlights, positively affects ratings, and the square of the number of likes negatively affects ratings. Our findings suggest that if viewers are overly satisfied with the highlights, some may be satisfied with merely viewing them and refrain from watching the actual show; such a response may potentially decrease TV viewership. This is the first study to examine the role of online video highlights as a promotional tool for TV shows.