The Lean Startup concept of iterative testing of ideas to validate concepts seems useful and efficient on face, but sometimes (theoretically many times) a test fails. This places the start-up at a critical juncture: Conclude that the test had demonstrated shortcomings and move on or conclude that the test was designed in a way that failed to effectively validate or invalidate the business concept. How is an entrepreneur to know with confidence that the business idea is being validated effectively via testing?Fortunately, for more than a decade, digital advertisers have been taking Internet technologies and using them to build closed loop attribution engines. By looking at the evolution of these technologies, how they work, and how they are applied to the paid acquisition and social media market, along with dozens of examples, we can understand how to build better start-ups and more successful revenue generation systems for every sort of business that leverages the Internet, including answering questions like:How do you most effectively gather data about digital customers?What are modern best practices in attribution?How can you calculate lifetime customer value?How do I analyze cohorts to improve conversion rates?What is the minimum effective dose of SEO for different kinds of web sites?How should tools like mobile, video, digital, remarketing, and behavioral targeting affect customer acquisition?When and how should I use virality to improve the effectiveness of customer acquisition?Different kinds of businesses require different kinds of growth engines. By answering these questions and more, you can understand what kind of business you are building, what customer acquisition techniques will be most effective, and how to test and scale each of these businesses.When I entered the digital advertising business, I was amazed at how complicated it was. There are different kinds of creative formats, different kinds of targeting, search, mobile, social, desktop, video, different kinds of attribution, and a million other factors that contribute to the success or failure of online advertising. In every aspect of these, there are people that specialize deeply. But modern entrepreneurs, growth hackers, and people working in digital need to have a broad understanding of every aspect of the industry, how the market works, and how to leverage it to your advantage.This is the book that I needed when I started working at Advertising.com. This is the book that I want to give to the companies that I advise when we talk about why they aren’t growing faster. This has all the tips and tricks with tons of examples and case studies.