When two parties quarrel, the third rejoices, according to a well-known proverb. This book highlights the role of rejoicing “profiteers” in political efforts to expand market-based competition. Marketization appears puzzling if it is conceptualized as a political struggle between the established incumbents and their challengers, or between producers and consumers. Challengers and consumers often lack the resources to overcome barriers to market entry, and collective action problems afflict both groups. Why, then, do incumbents fail to protect their turf? The present book resolves this puzzle by casting light in a new direction, toward those who profit from a contest while remaining above the fray. The rejoicing band of profiteers grows alongside the arena of competition. Once the suppliers of market support services have established themselves on the sidelines of a contest, they accumulate resources that help them expand that arena further. Political struggles surrounding the gradual marketization of corporate control in Britain, Germany, and France from the 1860s onward provide empirical illustration. The book maps and analyzes the path-dependent evolution of support for shareholder rights relating to takeover bids among key interest groups, including managers, creditors, shareholders, and takeover service providers, as well as among political parties. By comparing the self-reinforcing and self-undermining policy feedback of market-enabling and market-restraining rules, it helps explain why market containment is an uphill struggle, while market expansion becomes easier with time.