Tiered link building helps you build a strong backlink profile by layering...

https://qqpipi.com//index.php/How_Do_I_Use_Social_Bookmarking_Without_Getting_Spammy%3F

Tiered link building helps you build a strong backlink profile by layering links. Tier 1 are your main backlinks pointing directly to your site. Tier 2 links support Tier 1 by linking to those first-tier pages