What is a Cross-platform Alternative News Environment? Tracing Information Flow Across Nine Social Media Platforms based on Mutual URL Sharing

Contemporary news and opinion dissemination is characterized not by a fixed set of sendersand receivers, but by networked information flows and active curation by multiple types ofactors, from professional organizations, politicians and journalists to interest groups, punditsand opinionated individuals. Approaches to analyzing news dissemination on social medianeed to take stock of the broader information sharing environment that news sharing is part of.This study presents a general approach for analyzing large-scale information flows on socialmedia in a cross-platform context by tracing URLs. Using a selection of alternative news mediaoutlets from Germany, Austria, Sweden and Denmark as a starting point for operationalizingthe broader news sharing environment that alternative news content is shared within, this studytraces URL sharing across Facebook, Twitter (X), Instagram, YouTube, Reddit, Telegram,Vkontakte, Gab and 4Chan in multiple iterations of snowball sampling. A total of ~900 millionposts are collected, followed by a two-pronged analysis of 1) general cross-platform flows andplatform outflow/inflow dynamics and 2) cross-platform characteristics of networks based onrepeated mutual URL sharing among actors. Each part of the analysis considers both URLsthat simply appear on multiple platforms as well as those that are shared directly from oneplatform to another.Results show that one third of all URLs that appear in more than one post are cross-platform,with 17% being shared directly from one platform to another. Modelling mutual URL sharingbehavior as a network shows that only 16 – 24% of the network is strictly single platform.Additional specific platform dynamics are presented and discussed in relation to previousfindings on cross-platform content sharing.