Code set out as txt at the bottom of a web page!

Viruses and worms
1

On the cogento.com site I see this

<div style="display:inline;"> <img height="1" width="1" style="border-style:none;" alt="" src="//googleads.g.doubleclick.net/pagead/viewthroughconversion/995406578/?value=0&amp;label=d-ZZCM7qtAQQ8uXS2gM&amp;guid=ON&amp;script=0"/> </div>

displayed . Is this being blocked by a script blocker or other extension, Why it appears?
It is flagged by my malware script detector as if the code could be from a XSS attack.
Searching for it I land at this analysis: http://analysis.hsoub.com/websites/www.cogentco.com

polonus