The addition of these properties makes BuzzMedia the single largest independent publisher of music content on the web, according to comScore Media Metrix. Buzzmedia is already a fast-growing entertainment publisher and is behind such properties as Go Fug Yourself.

Services of the websites acquired range from providing fully legal mp3 downloads to live music coverage and introducing emergent artists.

But Tyler Goldman thinks the real moneymaking opportunity is in the deep dive, publishing endlessly about topics that lots of people care about. (Pop stars and music, anyone?)

So far, the idea has worked out. After Mr. Goldman’s social network, Buzznet.com, went live in 2006, it spawned a company, Buzzmedia, that now owns three dozen music and celebrity sites, including Celebuzz.com (a celebrity gossip blog) and Stereogum.com (alternative music news).

It’s akin to the financial world, said Mr. Goldman, Buzzmedia’s chief executive: “If you care about natural gas in Kazakhstan, you’re getting 60 articles about it. People have the same passion for Britney Spears.”

Now, the network is adding six sites to its arsenal, either as a partner or as a full owner, including PopMatters.com and Gorilla vs. Bear (gorillavsbear.blogspot.com), a site dedicated to independent music. The other additions are ConcreteLoop.com, PureVolume.com, RCRDLBL.com, and the Hype Machine (hypem.com).

This kind of “blockbuster strategy” — focusing on hits rather than the breadth of products — has a future in the digital age, according to a 2008 report by Anita Elberse, an associate professor at the Harvard Business School. In the markets she looked at for her study, music and videos, the most popular products, captured even more of the market than they previously did.

The company, which is based in Los Angeles and has a handful of other offices, employs 115 people full time. Of those, 60 help produce editorial content, much of it curated from material floating online. Hundreds of “super” users also provide content.

For people interested in a topic like alternative music, Mr. Goldman said, an online search can be inefficient, sometimes requiring several clicks. What his sites can provide, he says, is a one-stop experience — and that entices people to come back daily, making the sites themselves less reliant on the occasional vagaries of search engines.

So far, Mr. Goldman’s instincts have paid off. In April, Buzzmedia’s sites had 16.5 million unique users, according to comScore. The new additions, he said, could add a couple of million more.