  In the last two years, Artificial Intelligence Generated Content (AIGC) has
received significant attention, leading to an anecdotal rise in the amount of
AIGC being shared via social media platforms. The impact of AIGC and its
implications are of key importance to social platforms, e.g., regarding the
implementation of policies, community formation, and algorithmic design. Yet,
to date, we know little about how the arrival of AIGC has impacted the social
media ecosystem. To fill this gap, we present a comprehensive study of Pixiv,
an online community for artists who wish to share and receive feedback on their
illustrations. Pixiv hosts over 100 million artistic submissions and receives
more than 1 billion page views per month (as of 2023). Importantly, it allows
both human and AI generated content to be uploaded. Exploiting this, we perform
the first analysis of the impact that AIGC has had on the social media
ecosystem, through the lens of Pixiv. Based on a dataset of 15.2 million posts
(including 2.4 million AI-generated images), we measure the impact of AIGC on
the Pixiv community, as well as the differences between AIGC and
human-generated content in terms of content creation and consumption patterns.
Our results offer key insight to how AIGC is changing the dynamics of social
media platforms like Pixiv.
