social media networks and investigates influence within a network (see Sections 12.2 and
12.3.3
above, or Jackson and Yariv, 2011), many open questions remain about the role of
network structure in online social networks. Important directions for future research
include quantifying the value of network effects in these platforms, estimating the extent
to which they provide market power, and exploring the factors that allow a competitor to
overcome the network-effects barrier. For example, it could be that there is a tipping
point at which users move en masse from one platform to another.
A related element of competition occurs between social media and more traditional
media outlets. Wikipedia competes with traditional encyclopedias, blogs with newspa- ...