Google recently announced that all domains in search ad display URLs would appear in alllowercase. "For example, if your display URL is Subdomain.Example.com/Subdirectory, it will appear as subdomain.example.com/Subdirectory."
Fellow URL-aholics know this is not a best practice for making your domain easy to decipher. Yet, Google says, "Recently, we found that by standardizing the look of the URLs on the page, we were able to improve many of our user metrics, including ad clickthrough rates." Maybe that's because of all the accidental clicks resulting from people not being able to easily recognize the domain they're clicking on!
What does this mean for all the Google advertisers out there? Wherever possible, use Subdirectories for your search ad landing pages as opposed to Subdomains. On a crowded Google results page, if you want to stand out from the clutter and pre-qualify your clicks, use Camel Case Subdirectories to let searchers know what they should expect to find on your site.