YES. Since the internet is changing over to https (secure url), it has created a problem for traffic sites.
BuildAHive is a https website and can not show http:// urls in a frame. It does not mean that those sites are "bad", they just haven't switched to https yet.
So the browsers block this or give warnings/errors or show a blank white page and not the site. You may have seen those blank white pages happen.
To cater to all websites, BuildAHive looks at the url and will show a seperate tab for those who still use http (no "s"). Because it caters to both, you'll see two different styles while clicking email ads, and it stops people from wasting their advertising by having a blank white page show instead of their site.