US companies invested over $500 billion in 2021 in intangible brand capital, over 2% of GDP. During the past decade, US companies have also been growing their internal marketing capabilities, an often overlooked source of human capital. We discuss the private and social benefits of these intangible brand capital stocks. While the private returns to companies are fairly clear, the academic literature has been divided over the social benefits and costs of advertising and promotion, the two key investment vehicles. We also discuss the implications of brand capital for measured productivity.