Why "turn on personalization" undersells the problem
The ai-in-ecommerce pillar page covers AI product recommendations as one use case among twenty: a model reads behavior and purchase history and personalizes what a visitor sees. That's the right one-paragraph summary, and it's also where most coverage of this topic stops. In practice, recommendations aren't one system, they're several distinct decisions that happen to get bundled under one app.
The product page needs different logic than the cart. Email needs different timing than either. A brand-new product with zero behavioral history needs a completely different approach than a bestseller with years of purchase data behind it. Treating all of that as one "recommendation engine" setting is exactly how a well-intentioned personalization project ends up pushing the same three items everywhere and adding little value.