Domain Authority is a proprietary metric developed by Moz that scores websites from 1 to 100 based on their perceived ranking potential. The score aggregates factors like total linking root domains, quality of those links, and overall link profile health. A site with DA 70 will generally outrank a DA 30 site for the same keyword, all else equal, but DA itself doesn't directly influence Google's algorithm—Google has never confirmed using it. The score is logarithmic, meaning it's easier to move from DA 20 to 30 than from 70 to 80. New sites start around DA 1–10, most small businesses sit in the 15–35 range, established regional players hit 35–50, and national brands or major publishers reach 60+. Ottawa SEO Inc.'s portfolio properties range from DA 8 for newer niche sites to DA 42 for aged authority domains, depending on link-building history. In link-building, DA helps prioritize outreach targets. A backlink from a DA 50 news site typically carries more SEO weight than one from a DA 15 blog. We use DA alongside domain relevance and traffic estimates to vet guest post opportunities and partnership deals. A DA 25 site in your exact niche often delivers better results than a DA 60 general directory. DA updates monthly as Moz recrawls the web, so scores fluctuate. A drop doesn't always mean your site weakened—it might mean competitors gained links faster. Similarly, Ahrefs uses Domain Rating (DR) and Semrush uses Authority Score; none are interchangeable, though they correlate loosely. When evaluating domains for acquisition or link prospects, we check all three plus organic traffic trends to avoid over-relying on a single metric. Don't chase DA for its own sake. Google cares about relevance, content quality, and user signals. A DA 60 site with thin content won't rank well, and a DA 25 site with strong topical authority can dominate SERPs. Use DA as a rough filter in link prospecting, not a success metric for your own site.