Here's another interesting content and its all about "Why rankings remain after links disappear" posted by Rand Fishkin from the Moz blog site. Rand will discuss regarding the link echoes or what he called link ghosts. This is the effect of a link across the rankings and Google's link graph. This is a test over the last six months. Kindly visit this link for your reference and study this interesting content to benefit you in many ways. Link Echoes (a.k.a. Link Ghosts): Why Rankings Remain Even After Links Disappear - Whiteboard Friday - Moz