Grouping Backlinks into Three Quality Tiers: A Practical Framework Based on DR, Organic Traffic, and a Proprietary SPAM Metric

https://memeburn.com/2016/03/5-startups-that-will-help-you-automate-seo-related-processes-in-2016/

1) Why grouping backlinks into three quality tiers changes how you spend time and budget Are you still treating every link opportunity the same? That’s why outreach teams drown in mass emails and miss the handful of links that actually move