Ah shame, thanks for looking Bozza.
I think you could be onto something re: the Hyypia effect. 2010/11 you've got the excitement of the new ground, Championship football and the Gus Bus still roaring along at 120mph. Then we have the Palace playoffs, Poogate, Hyypia and the rest. Numbers drop...
Those numbers are interesting. Do you have page view data going back to 2008? A ten year look would be interesting to see if there's a jump up with all the people like me signing up in 2011.