“Ads by Goooooogle” vs “Ads by Google”
Something that is a frequent source of speculation on forums is why Google sometime uses “Ads by Goooooogle” instead of “Ads by Google”. They have now answered that question on the Inside AdSense blog.
[W]e thought “Ads by Goooooogle” would be a fun alternate version of “Ads by Google” for our AdSense ad units. They are both branding features we’ve tested, and we found that “Ads by Goooooogle” is often more memorable for users than “Ads by Google”, so you may notice either label appearing beside your ads at any given time.
So, there really is no reason for it.