Temporal influence over the Last.fm social network

    Several recent results show the influence of social contacts to spread
    certain properties over the network, but others question the
    methodology of these experiments by proposing that the measured
    effects may be due to homophily or a shared environment. In this
    paper we justify the existence of the social influence by considering
    the temporal behavior of Last.fm users. In order to clearly
    distinguish between friends sharing the same interest, especially
    since Last.fm recommends friends based on similarity of taste, we
    separated the timeless effect of similar taste from the temporal
    impulses of immediately listening to the same artist after a friend.
    We measured strong increase of listening to a completely new artist in a few hours period after a friend compared to non-friends representing a simple trend or external influence.
    In our experiment to eliminate network independent elements of taste, we improved collaborative
    filtering and trend based methods by blending with simple time aware recommendations based on the
    influence of friends. Our experiments are carried over the two-year
    "scrobble" history of 70,000 Last.fm users.

    Róbert Pálovics, András Benczúr
    The 2013 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining ASONAM 2013 Niagara Falls, Canada, August 25-28, 2013