There are dozens of reports of people noticing their CPC prices in Google AdWords jump through the roof. With the launch of a new AdWords quality score, a bug has been released and verified by Google to increase the bid price of well performing keywords and ads for no reason.
There are threads at WebmasterWorld and DigitalPoint Forums with examples:
I've had about 20 keywords go to the £5.00 minimum today, all others stayed the same. These keywords were ok at 15p yesterday.
I'm also seeing keywords go inactive, increase min. bids to $10.00. But these inactive keywords are still showing up for searches.
I had a group of keywords that we were spending $200/day on go inactive and require a minimum bid of $10 to reactivate. No one else is bidding on these keywords anymore so I bet they're also having the same problems.
Jeremy Mayes has an email from Google confirming the issue:
Unfortunately, due to a technical issue, you may notice that the minimum bids for some of your keywords increased dramatically, despite them being high performing, good quality keywords. This is a temporary issue that our engineers are aware of and they are working to resolve it as soon as possible. I am sorry for any inconvenience.
I have received several other reports that Google is working on this issue now.
Don't forget this bug released today: Google Advertiser Charged For Paused Campaign in AdWords.
Forum discussion at WebmasterWorld and DigitalPoint Forums.