AdSense has been a mess for over a month now. Rich Media 728x90 ads are taking forever to load; I am constantly seeing "waiting for www.gstatic.com" messages in Firefox. They are doing so much back end stuff in Google these days that I am convinced it's taking a toll on AdSense publishers. CPC prices are also fluctuating more than I've ever seen before. I have a very steady pool of advertisers; 99/100 times when I check it's the same 3-4 advertisers. Yet prices in the last 4 days look like this.
Day 1 $0.60 CPC
Day 2 $0.50 CPC
Day 3 $0.21 CPC
Day 4 $0.58 CPC
On day 3 did Google just decide to bank away more earnings? Or perhaps reporting had issues and it really wasn't as low a CPC day as they are reporting? It's not believable to see CPC price swings like this. I have too many traffic and history in the account to believe the data I am seeing recently.