Meta descriptions have zero direct ranking weight in Google's algorithm, but they're still critical for SEO because they control what searchers see in the SERP snippet. When your description is compelling and matches search intent, you pull more clicks from the same ranking position. Higher CTR from organic results sends a behavioral signal to Google that your page satisfies the query better than competitors at similar positions, which can lead to ranking improvements over weeks or months. The mechanism is simple: if you rank fourth but get a CTR closer to what position two typically gets, Google notices. We've seen pages climb one to three spots after optimizing meta descriptions alone, though the effect takes 4–8 weeks to materialize and depends on query volume. Google rewrites meta descriptions roughly 60–70% of the time, pulling text from your page content instead. They do this when your written description doesn't match the specific query or when it's too generic. You can't prevent rewrites entirely, but tightly aligning your description with your primary keyword and the page's actual content reduces how often Google ignores it. Effective meta descriptions are 140–155 characters, include the primary keyword naturally in the first half, and communicate a clear benefit or answer. Avoid keyword stuffing or making promises the page doesn't deliver, because that spikes bounce rate and tanks the CTR benefit. At Ottawa SEO, we write meta descriptions for commercial pages and high-volume informational content, but skip them on low-priority blog posts where Google's auto-generation often performs adequately. We also A/B test descriptions on key landing pages by watching Search Console CTR data over 30-day windows. Small wording changes—swapping "learn how" for "get the exact process"—can shift CTR by 2–4 percentage points, which compounds when you're getting thousands of impressions monthly. The ROI on meta description optimization is high relative to effort, especially for pages already ranking in positions 3–10 where CTR variance is widest.