An advertiser will miscoded their ad and it wasn't picked up as it should in the programmatic system so it shows up blank. Don't worry, you will still get paid for it. However, let's leave nothing to chance and if you see it often when you are not logged into your blog, send us a quick email to help@ and we'll investigate it for you.

Another reason you might see a blank space on your blog is that you're logged into Wordpress. Being logged in while you're browsing can create caching issues with your ads. It's not a problem, it just means your ads will appear blank to you while you're browsing. Logging out of WordPress should result in seeing your ads again.