This paper considers how news aggregators affect the quality choices of newspapers competing on the Internet. To provide a microfoundation for the role of the aggregator, we build a model of multiple issues where newspapers choose their quality on each issue. The model captures both "business-stealing" and "readership-expansion" effects of the aggregator. We find that the aggregator leads newspapers to specialize their news coverage, and changes quality choices from strategic substitutes to strategic complements. Overall, the aggregator tends to increase the quality of newspapers and social welfare, but affects newspapers' profits in an ambiguous manner.