Core Web Vitals matter for two concrete reasons: they're a confirmed Google ranking factor since June 2021, and they correlate strongly with conversion rates and bounce rates in real user behavior. The three metrics measure what actually frustrates users. Largest Contentful Paint (LCP) tracks how long your main content takes to load—Google wants under 2.5 seconds, but we see most Canadian e-commerce sites sitting at 3.5–4.5 seconds on mobile. First Input Delay or Interaction to Next Paint (INP as of March 2024) measures how quickly your page responds when someone clicks a button or fills a form—delays over 200ms feel sluggish. Cumulative Layout Shift (CLS) penalizes pages where content jumps around while loading, like when an image loads late and shoves text down the screen. The ranking impact isn't massive on its own. A site with poor Core Web Vitals but strong topical authority won't vanish from page one. But when you're competing against similar content quality, vitals become the tiebreaker. We've seen Toronto service businesses jump 3–7 positions after fixing LCP issues, simply because they were already close in other signals. More importantly, the business impact shows up fast. A major Canadian retailer we consulted improved LCP from 4.1s to 2.3s and saw bounce rate drop 11% within two weeks—no other changes. People don't consciously notice Core Web Vitals scores, but they absolutely notice when a page feels slow or janky. The metrics also expose technical debt. Poor LCP often means oversized images, render-blocking JavaScript, or slow server response times. Bad CLS usually points to missing width/height attributes on images or ads loading asynchronously. These aren't just SEO problems—they're user experience problems that happen to be measurable. At Ottawa SEO, we treat Core Web Vitals as hygiene factors, not magic bullets. Fix them to remove obstacles, but don't expect vitals alone to carry a weak content strategy. They matter most for commercial pages where every percentage point of bounce rate costs real revenue.