Not sure if I just haven't been paying attention but...I'm noticing that there is an "Optimal" setting in the Adsense interface for both font size and font family. Not sure when this was introduced but suddenly, all the ad titles for my ads went from bold to not bold. I thought it was a change in font weight but, after further investigation I found that all my ad's font settings were set to Optimal. This had the effect of changing the font family to something other than what it was in the past (I think Arial). So, the weight of the font didn't change but the weight of various font families is so different that when this happened, it was like turning off a bold setting. The result has been a reduction in CTR over the past week or so.

I've gone in and changed the font to a specific font and we'll see what we shall see.

Wondering if anyone else has noticed this? Seems G is slowly working toward more options for text ad layouts but this caught me by surprise. Well, either that or I've been sleeping at the wheel on this one. Anything's possible. ;)