Charli XCX joined Substack in November. Monica Schipper/Getty Images Share on Facebook Share on X Google Preferred Share to Flipboard Show additional share options Share on LinkedIn Share on Pinterest Share on Reddit Share on Tumblr Share on Whats App Send an Email Print the Article Post a Comment Paid subscriptions to U.K.-based publishers and creators have officially surpassed half a million on Substack, in exclusive new data released to The Hollywood Reporter.