Meta descriptions matter for one primary reason: they control what searchers see before they click. Google displays your meta description roughly 40-60% of the time in search results. When they don't use yours, they pull text from your page that matches the query, which is often less compelling. The real value is behavioral, not algorithmic. Google confirmed in 2009 that meta descriptions aren't a ranking factor, but CTR absolutely influences your performance. If your result gets clicked more often than position 4 competitors, Google interprets that as a relevance signal. We've seen pages climb 2-3 positions purely from CTR improvements after rewriting meta descriptions, with no other changes. A good meta description does three things: includes the primary keyword so Google bolds it in results, communicates clear value in 140-155 characters, and differentiates you from competitors in the SERP. For local businesses in Ottawa or Toronto, adding location and specific services works better than generic benefit statements. "Ottawa basement waterproofing, 48-hour response, 10-year warranty" outperforms "Expert waterproofing services for your home." The length matters because Google truncates around 155-160 characters on desktop, less on mobile. Writing 180-character descriptions wastes the cut-off portion, and going under 120 characters misses opportunity. We test meta descriptions the same way you'd test ad copy, because that's functionally what they are. Key mistakes to avoid: duplicating meta descriptions across pages kills their effectiveness, stuffing keywords makes them unreadable and reduces CTR, and writing for bots instead of humans wastes the entire purpose. Every product page, service page, and blog post should have a unique meta description that makes someone want to click your result over the nine others on page one. At Ottawa SEO, we rewrite meta descriptions during content audits specifically for underperforming pages with decent rankings but low CTR. It's one of the fastest wins in on-page optimization, typically taking 15-20 minutes per page and showing CTR changes within two weeks in Search Console data.