Tiered link building uses two levels of links to boost your site’s SEO. Tier 1...

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

Tiered link building uses two levels of links to boost your site’s SEO. Tier 1 links point directly to your site, giving it strong, high-quality signals. Tier 2 links support those Tier 1 links, increasing their power and helping your SEO grow naturally