  In the evolving landscape of scientific publishing, it is important to
understand the drivers of high-impact research, to equip scientists with
actionable strategies to enhance the reach of their work, and to understand
trends in the use of modern scientific publishing tools to inform their further
development. Here, we study trends in the use of early preprint publications
and revisions on ArXiv and the use of X (formerly Twitter) for promotion of
such papers in computer science and physics. We find that early submissions to
ArXiv and promotion on X have soared in recent years. Estimating the effect
that the use of each of these modern affordances has on the number of citations
of scientific publications, we find that peer-reviewed conference papers in
computer science that are submitted early to ArXiv gain on average $21.1 \pm
17.4$ more citations, revised on ArXiv gain $18.4 \pm 17.6$ more citations, and
promoted on X gain $44.4 \pm 8$ more citations in the first 5 years from an
initial publication. In contrast, journal articles in physics experience
comparatively lower boosts in citation counts, with increases of $3.9 \pm 1.1$,
$4.3 \pm 0.9$, and $6.9 \pm 3.5$ citations respectively for the same
interventions. Our results show that promoting one's work on ArXiv or X has a
large impact on the number of citations, as well as the number of influential
citations computed by Semantic Scholar, and thereby on the career of
researchers. These effects are present also for publications in physics, but
they are relatively smaller. The larger relative effect sizes, effects of
promotion accumulating over time, and elevated unpredictability of the number
of citations in computer science than in physics suggest a greater role of
world-of-mouth spreading in computer science than in physics.
