The unique characteristics of the search advertising industry encourage the development of anticompetitive monopoly power, facilitating the rise and dominance of companies like Google. First, the search advertising industry is subject to multi-sided network effects that create a positive feedback loop. An increase in the number of customers on one side of the market attracts increased numbers of customers on the other side, enabling dominant firms to entrench their market power. Second, and relatedly, the search advertising industry operates in an innovative market where firms compete not to outdo competitors on price but rather to displace one another’s products entirely. In such a market, a dominant firm can acquire potentially displacing (but not substitutive) technology and thereby control future innovation, freeing itself from the burden of innovating further to maintain competitive advantage. Current regulatory enforcement, informed by traditional antitrust analysis, does not adequately account for the impact of multi-sided network effects or innovation-to-displace on competition. Retooling the regulatory regime governing merger enforcement, allowing the agencies tasked with enforcement to broaden their inquiries when investigating anticompetitive behavior of these firms, is therefore necessary to preserve competition in multi-sided innovative markets.