  The creation and sharing of memes is a common modality of online social
interactions. The goal of the present work is to better understand the
collective dynamics of memes in this accelerating and competitive environment.
By taking an ecological perspective and tracking the meme-text from 352 popular
memes over the entirety of Reddit, we are able to show that the frequency of
memes has scaled almost exactly with the total amount of content created over
the past decade. This means that as more data is posted, an equal proportion of
memes are posted. One consequence of limited human attention in the face of a
growing number of memes is that the diversity of these memes has decreased at
the community level, albeit slightly, in the same period. Another consequence
is that the average lifespan of a meme has decreased dramatically, which is
further evidence of an increase in competition and a decreasing collective
attention span.
