Photo by Vanna Phon on Unsplash Customer acquisition is the lifeblood of many startups from e-commerce to gaming to marketplace companies, among others. Most of these startups spend the lion’s share of their marketing budget in today’s social media channels: Facebook, Twitter, Reddit, Snap, TikTok and so on because — no surprise — that’s where the customers are. Digital advertising spend is projected to grow 25% this year to $191 billion, and Google (69%), Facebook (59%), Snapchat (116%) and Twitter (87%) all just reported rapid growth in their year over year advertising revenues. For these companies, it looks like a rosy picture. But if you ask anyone in the ecosystem of customer acquisition — founders, marketers, investors — and you’ll hear the same thing: customer acquisition (CAC) is g