Unilever has agreed to buy the Dollar Shave Club subscription grooming service for a whopping $1 billion, giving the world's second biggest ad spender an entry into one of the most profitable segments of personal care, and Dollar Shave Club a platform for global expansion.

The deal puts Unilever even more in competition with its long-time rival Procter & Gamble Co., whose Gillette brand still dominates men's shaving globally and in the U.S., with a roughly 80% share of razor cartridges sold in stores in the U.S., according to Nielsen data from Deutsche Bank.

Michael Dubin, founder and CEO of Dollar Shave Club, will stay on as CEO, Unilever said in an announcement. Dollar Shave had an unnamed "strategic investor" in venture funding, one that turned out to be Unilever.

While sales of Dollar Shave Club weren't disclosed, Unilever said the brand had 3.2 million members, and as of last month company executives said they expect to have $240 million in sales this year. With its venture-funded, internally created ads, Dollar Shave has rivaled Gillette for leadership in TV spending in recent years.

As of last year, Dollar Shave claimed to have passed Edgewell Personal Care's Schick to become the number one men's razor cartridge brand by volume in the U.S., and it's added about a million members since then. The e-commerce brand also sells a variety of other personal-care items for men, including One Wipe Charlies "butt wipes," Big Cloud skincare and Boogie's haircare products.

"Dollar Shave Club is an innovative and disruptive male grooming brand with incredibly deep connections to its diverse and highly engaged consumers," said Kees Kruythoff, president of Unilever North America, in a statement. "In addition to its unique consumer and data insights, Dollar Shave Club is the category leader in its direct-to-consumer space. We plan to leverage the global strength of Unilever to support Dollar Shave Club in achieving its full potential in terms of offering and reach."