ToplineLeonid Radvinsky, a Ukrainian-born entrepreneur who after a teeenage career profiting off spam and porn websites made billions—$1.9 million a day, Forbes once reported—as the reclusive owner of the porn-creator site OnlyFans, died of cancer at 43, a company spokesperson said Monday.Radvinsky purchased OnlyFans in 2018. (Photo by Jakub Porzycki/NurPhoto via Getty Images)NurPhoto via Getty ImagesKey FactsRadvinsky died “peacefully after a long battle with cancer,” an OnlyFans spokesperson told Forbes Monday morning.Radvinsky purchased OnlyFans in 2018, transforming the fan subscription service that lets users pay for exclusive content from creators from a niche website to a hugely popular porn business, which Forbes reported was making him $1.9 million per day in 2024.OnlyFans’ burgeoning popularity, which skyrocketed during the Covid-19 pandemic, lifted Radvinsky’s fortunes, with Forbes naming him a billionaire in 2021, and he more than doubled his net worth to $4.7 billion by the time of his death.But OnlyFans was far from Radvinsky’s first venture as a porn mogul, as the secretive billionaire—who never gave interviews—first built a shady business as a teenager in which he operated websites that claimed to lead users to porn content involving underage children or bestiality.A previous Forbes investigation found no evidence these websites really linked to the content they promised, but Radvinsky still made money off of every click.Radvinsky’s early career may have been murky and legally dubious—he settled lawsuits from both Amazon and Microsoft, who objected to the use of their company names in apparent spam campaigns—but his porn entrepreneurship made him millions long before he bought OnlyFans, Forbes previously reported. Forbes ValuationRadvinsky was worth $4.7 billion at the time of his death, according to Forbes estimates, making him the No. 869 wealthiest person in the world. He ranked No. 181 on the 2025 Forbes 400 ranking of the wealthiest people in Am