Over the past 3 weeks I've been trying various things out and thought I'd share, for whatever it's worth. I tried one change (eg only change background color) per week from the "control group". Control: Background - white Title - same as website text Description - same as website text URL - same as website text Week 2: Title - 10%-30% darker than website text Results - slightly lower than control (probably not enough data) Week 3: Background - light yellow/manila Results - 50% less effective than control group. Sucked wind. Question --- Is it against guidelines to have the ad URLs same color as background so you cannot see it? Couldn't find anything in the terms of service....