Link Memory: SEO Experiment Result
In April 2014 an experiment designed to test the influence of anchor text on URL rewriting showed positive results. Google chose inbound link anchor text value to override uninformative page title in SERPs. After the first stage of the experiment had concluded we removed all inbound links to the test page.
The second part of the experiment was to test the link memory phenomenon, or in other words to see how long would Google use signals from non-existent links.
Title replacement lasted for 205 days (6 months and 22 days) suggesting that link signals can indeed outlast the links themselves for a significant amount of time.
Our page is no longer in Google’s index so the experiment cannot continue but we have solid proof of link signals impacting a page for at least 6 months after link removal.
Googlers have said in the past that link signal detection depend on many factors including the rate/speed of page and link indexing. For example a page that rarely gets crawled could have a sustaining impact with the last known snapshot of that page’s links. This issue is of particular interest to those who are attempting to clean up their link profile.