Strengthen existing tier 1 guest posts with measured social signals, tier 2...

https://source-wiki.win/index.php/Why_My_Niche_Edit_Link_Is_Not_Moving_Rankings

Strengthen existing tier 1 guest posts with measured social signals, tier 2 links, click-through and clickstream activity, and relevant referral traffic. The goal is to support pages already earning links, not simply add more placements