On the day before Thanksgiving, Bustle CEO Bryan Goldberg got an urgent call from his counterpart at millennial news site Mic, Chris Altchek. Mic was in dire financial straits. Months of effort to find a buyer had fallen apart. Mr. Goldberg, who was friendly with Mr. Altchek, had resisted getting involved previously because he didn’t want to participate in a bidding war. But the war was over. Mr. Altchek asked Mr. Goldberg to step in.

And so within a week Bustle—known for female-focused culture and fashion content—reached a deal to buy Mic for less than $10 million, a fraction of its valuation from just 18 months ago of around $100 million. It was Bustle’s fourth fire-sale acquisition in the past 18 months, including of high-profile names like Gawker.com, each for just a few million dollars. It was confirmation of Mr. Goldberg’s self-styled status as the “buyer of last resort” in digital media.