Sponsored search advertising has become an important venue for firms to compete for consumers. As a result, many keywords attract a large number of bidders, where the competing advertisers could be quite heterogeneous. We examine whether this heterogeneity impacts how consumers perceive and react to such competitions. Toward this end, we draw on the theory of strategic groups to prescribe the structure of the competitive environment, and investigate how strategic groups impact consumers’ clicking and website visiting behavior when viewing sponsored search results. Our unique datasets that combine search results from Google and consumers’ clickstream data enable us to disentangle such an impact. We find strong positive externality for within-group competitors relative to across-group competitors: (i) consumers are more likely to co-visit two firms that belong to the same strategic group as opposed to two firms from different groups when both firms appear in a search result; (ii) the presence of a firm in a search result primes consumers to visit other firms from the same strategic group even when the other firms do not appear in the search result. Our findings contribute to the sponsored search and strategic group literature by theorizing and empirically verifying consumers’ website visit behaviors from the strategic group perspective.