Optimizing Your AdWords Campaign Using Google’s Adwords Campaign Experiments (ACE)

Google’s AdWords Campaign Experiments are a great evaluate changes that you make to your account and test if they have a positive or negative result on your cost per acquisition (CPA) and conversion rates.

Google Instant: Why you’ll be paying more in your AdWords budget

Google’s instant search may start driving up the cost of PPC campaigns by increasing impressions, decreasing click through rates and decreasing quality scores.