Did Google Panda 4.0 Go After Press Release Sites?

Nine days ago when Google released Panda 4.0 – which aims to filter out “thin” content from top rankings – we focused our attention on the big Winners & Losers charts, Since then, some have noted that press releases may have also been hit big time.

Using SearchMetrics, I looked at the top Press Release sites and checked if they lost any SEO visibility on a large scale since Panda 4.0 hit, and PRWeb.com, PR Newswire, BusinessWire and PRLog all seem to have lost significant rankings in Google.PRNewsWire.com seems to have shown a significant drop in SEO visibility, dropping ~63% after Panda 4.0 was released:

Source:http://searchengineland.com/google-panda-4-0-go-press-release-sites-192789