If three’s a trend, then digital media mergers are officially a thing.

Group Nine Media announced on Monday that it had bought PopSugar, a multimedia entity with an audience of millennial women.

Group Nine — the publisher of the viral-video site NowThis, the animal site The Dodo, the food-drink-and-lifestyle site Thrillist and other outlets — declined to disclose the terms of the deal. Group Nine said it was an all-stock transaction.

Last week, Vice Media bought Refinery29 in a mostly stock deal valued around $400 million. The week before, Vox Media pulled off an all-stock purchase of New York Media, the company behind New York magazine and its digital offshoots.

PopSugar started in 2006 as a blog run by the husband-and-wife team of Brian and Lisa Sugar. It now includes a shopping platform, a cosmetics line and a festival business. Mr. Sugar said in a statement that joining forces with Group Nine allowed his digital brand “to build a scalable business model that sets the standard for the next-generation media company.”