What is the Google Dampening Link Filter, and is it real?
The Google Dampening Link Filter theory suggests that if Google detects a sudden increase (i.e. many hundreds or thousands) in the number of links back to your site, it may sandbox them for a period (or in fact penalize you by lowering your ranking or blacklisting your site altogether). There is a lot of anecdotal evidence supporting the theory, but there is also a lot discounting it. No one has categorically proven its existence.
