  Facebook pages offer an easy way to reach out to a very large audience as
they can easily be promoted using Facebook's advertising platform. Recently,
the number of likes of a Facebook page has become a measure of its popularity
and profitability, and an underground market of services boosting page likes,
aka like farms, has emerged. Some reports have suggested that like farms use a
network of profiles that also like other pages to elude fraud protection
algorithms, however, to the best of our knowledge, there has been no systematic
analysis of Facebook pages' promotion methods.
  This paper presents a comparative measurement study of page likes garnered
via Facebook ads and by a few like farms. We deploy a set of honeypot pages,
promote them using both methods, and analyze garnered likes based on likers'
demographic, temporal, and social characteristics. We highlight a few
interesting findings, including that some farms seem to be operated by bots and
do not really try to hide the nature of their operations, while others follow a
stealthier approach, mimicking regular users' behavior.
