A few weeks ago, one of our clients accidentally released duplicate description tags across all the pages in one section of their site.
They were using template based formats for the descriptions so that every page would have a unique description but the system failed and every description ended up being identical.
The effect on performance for these pages was instant and significant.
There was an immediate drop in entry visits of about 33% the day following the release.
The problem was identified and the fixed was release 9 days later. The recovery in traffic to previous levels was also effectively instant.
This clearly shows the harm that a duplicate description tag can have on a page’s performance. You’re better off not having a description tag than a duplicate.
DeepCrawl, our site management tool, has a report that shows all the duplicate descriptions on a website site so we’re recommending all our clients take a close look at their reports and see if there is an opportunity for improvement.