Google's advertising revenues are not down 5%. Google's total revenue is up 19% year over year and 1% quarter over quarter. All categories of revenue are up except for network revenue (which is up 7% Y/Y but down 2% Q/Q).

You may be thinking of the share price which in after hours trading dropped 5% but recovered most of that this morning. Or perhaps you're thinking about the Cost-Per-Click metric which decreased somewhere around 5%.

http://investor.google.com/pdf/2013Q2_google_earnings_slides...