News aggregators have emerged as an important component of digital content ecosystems, attracting traffic by hosting curated collections of links to third party content, but also inciting conflict with content producers.
Aggregators provide titles and short summaries (snippets) of articles they link to. Content producers claim that their presence deprives them of traffic that would otherwise flow to their sites. In light of this controversy, we conduct a series of field experiments whose objective is to provide insight with respect to how readers allocate their attention between a news aggregator and the original articles it links to. Our experiments are based on manipulating elements of the user interface of a Swiss mobile news aggregator. We examine how key design parameters, such as the length of the text snippet that an aggregator displays about articles, the presence of associated images, and the number of related articles on the same story, affect a reader’s propensity to visit the content producer's site and read the full article. Our findings suggest the presence of a substitution relationship between the amount of information that aggregators offer about articles and the probability that readers will opt to read the full articles at the content producer sites. Interestingly, however, when several related article outlines compete for user attention, a longer snippet and the inclusion of an image increase the probability that an article will be chosen over its competitors.