Instantly transforms your blog into an s-blog! Change your classic blog or shopping site into a fun social networking site (SNS) around your posts and
Visit http://www.pivto.com and simply sign up.
You should configure it, visiting the "pivto" tab in the admin's left pane.
Probably you have not activated it yet. Please check your settings in Pivto's tab within your WordPress administrator or visit http://www.pivto.com and login to check if "embedding" is enabled.