The proof is in the profit. McKinsey & Company finds that companies are seeing monetary gains from adopting AI. Grace Cary/Getty Images McKinsey & Company found that AI is delivering monetary gains in an analysis of 20 companies. McKinsey says AI adoption at those companies boosted profits by 20% after 2 to 4 years. The companies succeeded by focusing on key domains rather than widespread implementation. AI might finally be paying off. For all the hype, there's been lingering skepticism about whether AI is actually delivering financial returns. Companies have adopted all sorts of creative metrics to measure — or at least approximate — the potential gains from AI adoption. Some are tracking the number of users a particular AI tool has, or the amount of time workers are saving using AI. To most companies, though, it's the bottom line that matters most — and McKinsey & Company says the numbers are starting to look promising.…