Tiered link building helps boost your website’s authority by creating two...

https://www.4shared.com/office/BIObF2h6fa/pdf-72309-44204.html

Tiered link building helps boost your website’s authority by creating two levels of backlinks. Tier 1 links point directly to your site and are high quality. Tier 2 links support your Tier 1 links, making them stronger and more effective