Tiered link building is a strategy that helps boost your site’s ranking by...

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

Tiered link building is a strategy that helps boost your site’s ranking by creating two levels of backlinks. Tier 1 links point directly to your site and have the most value. Tier 2 links point to your Tier 1 links to strengthen them