Above, Search Engine Land shows traffic plunge for Businesswire for certain search terms.
Google's latest algorithm update, Panda 4.0 appears to be punishing sites that host and distribute press releases, by demoting them in its search rankings reports Barry Swartz at Search Engine Land:
since Panda 4.0 hit... PRWeb.com, PR Newswire, BusinessWire and PRLog all seem to have lost significant rankings in Google.