Tiered link building uses two levels of backlinks to boost your site’s...

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

Tiered link building uses two levels of backlinks to boost your site’s authority. Tier 1 links point directly to your site from high-quality sources. Tier 2 links support those Tier 1 backlinks, helping them rank better and pass more value