Hi, I was just wondering if there's anyone here who saw a huge drop in traffic during May/June 2010 and never saw traffic recovered even during shopping season. I never made any major changes in the last 12 months so I still don't quite know why google took away 20% of my traffic in less than 60 days.
Yes, May was the beginning of an extended series of algorithm changes that we began calling the Mayday Update. Many people here saw a traffic drop - some have recovered by now and some have not.
According to Matt Cutts, the purpose of the change was to improve the long tail SERPs for Google users, and the reports we see here support that idea - the major traffic changes occurred in long tail traffic.
There are two threads that are very worth reading to catch up on our discussion:
One of the basic ways to check is by comparing your total keyword base pre and post May/June time-frame. This can give an idea if there was any major drop in number of ranking keywords which might have attributed to the drop in traffic.