<http://schema.org/description>
"Google Pay Per Action has been having limit beta testing since March 21st.  Advertisers who have access to create ppa ads, want more publishers to offer them.\n\n\nA WebmasterWorld thread has the same to"^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.seroundtable.com/archives/013884.html>