guggi2000 - 5:51 am on May 7, 2013 (gmt 0)
Our site is informational (education) but fell also. We are seeing a site -wide drop, a drop in direct, referral and search engine traffic and worldwide.
1. Could it be that some external event, such as the Boston marathon on 04-15 made people change their internet behavior for ONLY a few days, which then sent (temporarily wrong) signals to Google (i.e. "time on site"), which then updated the SERP based on these updated (and temporarily wrong) signals? That would mean that it would fall back at some stage.
2. Personally, I think it is rather coincidence and Google roled out something on 04-15, such as the Panda/Pinguin in the core algo. Such an update could lead to fluctuation, ongoing changes. But how can you explain the drop in referral traffic? (it is not seasonal)