     A Facebook spokesperson suggested that professionals who
met at a conference might be among people who would find use for
this feature, as well as recruiting managers looking to contact
a potential job candidate. These are similar reasons that people
use LinkedIn’s InMail, however, there are some differences
between the products. InMail is part of a LinkedIn premium
account, which users pay monthly subscriptions for. In this
test, Facebook provides the option to pay a small amount on a
case-by-case basis. InMail allows LinkedIn users to contact
people they would not otherwise have been able to message,
whereas Facebook is allowing people to pay for priority
delivery, not the message itself. LinkedIn also guarantees a
response, and if a sender does not get a reply within a week,
they can send another InMail message for free. Facebook is not
currently testing anything like this, but the social network
does show read receipts when a message has been viewed.  Public
figures who have enabled subscribers will