Outsmart Bad Link Vendors: What You'll Achieve in 30 Days
https://www.scribd.com/document/980484521/Are-DR-30-Links-Worthless-Compared-to-DR-70-A-Straight-Answer-for-Marketers-219924
If you've been burned by link-building providers who promise the moon, refuse to show traffic data, or hand you a spreadsheet of low-quality URLs, this guide is written for you