Você precisa instalar pelo menos um dos pacotes account-plugin-*
; por exemplo:
account-plugin-aim
account-plugin-evernote
account-plugin-facebook
account-plugin-fitbit
account-plugin-flickr
account-plugin-foursquare
account-plugin-gadugadu
account-plugin-google
account-plugin-groupwise
account-plugin-icons
account-plugin-icq
account-plugin-identica
account-plugin-instagram
account-plugin-irc
account-plugin-jabber
account-plugin-linkedin
account-plugin-mxit
account-plugin-myspace
account-plugin-salut
account-plugin-sametime
account-plugin-sina
account-plugin-sip
account-plugin-sohu
account-plugin-tools
account-plugin-twitter
account-plugin-ubuntuone
account-plugin-windows-live
account-plugin-yahoo
account-plugin-yahoojp
account-plugin-zephyr