Can Competitors Negative SEO Hurt You On Google?

A number of us have noticed that when we get extra links to our sites they actually fall in the SERPs and this seems to be confirmed by experimentation – OK, results may be skewed by algo changes but it seems pretty coincidental that on so many occasions a site falls very soon after the new links appear. This may mean that competitor’s sites could be pushed down the SERPs by unscrupulous operators buying spammy links which are pointed at them.