A WebmasterWorld thread reports many advertisers upset with recent changes they saw applied to their Google AdWords. Many saw a bunch of their keywords drop automatically into the "inactive keywords" bucket. Here are some of those reports;
I left with 23,000 inactive keywords. Today, I have 35,000. Traffic dropped 30% from what it used to be.
I had about 23,000 active and today I have only about 12,000 active.
AdWordsAdvisor comes in and gives the explanation as to why this has happened yesterday;
The primary component of the change is that, in non-USD currencies, we've "rounded" many of the minimum CPC amounts so that they'll no longer appear as rather odd amounts - as requested by many advertisers, globally. Note that this change effects 'lower quality ads' (i.e. those at high minimum CPCs) more than high quality ads - thus, for example, a keyword at 0.04 wouldn't have been rounded to 0.05, but a keyword at 4.14 would have been rounded to 4.00.
Related to this change, we've added more 'granular' minimum CPCs between $0.05 and $0.20, specifically at $0.06, $0.08, and $0.15. Some advertisers have been frustrated by the jump in minimum CPCs above $0.05, so this should help alleviate that frustration. As a result, some advertisers will see small increases in their minimum CPC, as has been noted in this thread.
Overall, this change is very small, although some individual advertisers may see bigger changes.
Please note that this is not related to landing page quality.
I guess some folks noticed this very small change.
Forum discussion at WebmasterWorld.