Unfriend app and strange links

This evening I had to make some changes to a website and noticed something strange in my browser, the site had links in the text I had not put in there. For example this was added to the word complete in the code "<nobr><a id="FALINK_1_0_0" class="FAtxtL" href="#">complete</a></nobr>"

I started to get suspicious, did Comcast add advertisements to the websites I visit? does my web host make some extra money? no, finally the text in the advertisements, "Friend Checker" did lead me to the clou, it was the UnFriend App in Firefox that created the extra code....after disabling the UnFriend app the adds were gone.