YouTube TV, Google’s entry in the crowded market of live TV streaming services, is now available in ten more U.S. metros, the company announced this morning. In nine of the ten markets, the service will include the live local feeds from all four major broadcasters – ABC, CBS, FOX and NBC. The ability to watch live television from major broadcasters has been one of YouTube TV’s differentiated features since its debut, as it chose to go forgo nationwide availability in favor of a promise to deliver broadcast channels in the markets it serves.

Initially, the service was available only in top U.S. metros including L.A., New York, Philadelphia, Chicago, and the San Francisco Bay area.

As YouTube Chief Business Officer Robert Kyncl explained in February when the service was first unveiled, the goal is to offer “comprehensive national coverage with ABC, NBC, CBS, Fox all included” on YouTube TV, so users wouldn’t have to miss out on those “can’t miss” live TV moments, he said.

The company in June said at the VidCon industry conference that it would soon triple its footprint with launches in 10 more metros. Those are the same markets that are actually going live today.

This includes: Washington, D.C., Houston, Atlanta, Phoenix, Detroit, Minneapolis-St. Paul, Miami-Ft. Lauderdale, Orlando-Daytona Beach-Melbourne, Charlotte, and Dallas-Fort Worth.

In all of the markets except Dallas-Fort Worth, streamers will be able to watch live TV from ABC, CBS, FOX, and NBC. The Dallas-Fort Worth market has CBS, FOX and NBC, but only on-demand prime-time programming from ABC. (It’s still possible that this could change in the future, as new deals are forged).

While access to major broadcast channels is one of YouTube TV’s bigger draws, the service has been expanding its cable lineup as well since its April debut. It has added AMC, BBC World News, BBC America, IFC, WE tv, Sundance Channel, Olympic Channel, Telemundo and Universo to its existing offering, which had first arrived with a number of other top networks, like CW, USA, FX, FXX, Syfy, FreeForm, MSNBC, CNBC, Fox News, Fox Business, Disney, Disney Jr., NatGeo, Sprout, E! and others.

In total, YouTube TV now offers nearly 50 networks, including also sports from ESPN, NBC Sports and Fox Sports.

YouTube TV is challenging services like Sling TV, PlayStation Vue, DirecTV Now, and Hulu’s Live TV service in the live TV streaming space. The services are often very similar in terms of feature set – they all offer cross-platform viewing, for example, as well as cloud DVRs (or at least are in the process of rolling them out), and they let multiple users watch at once.

Besides access to broadcast channels, YouTube TV’s key features are a low price point ($35/mo); an unlimited cloud DVR; six accounts per household; three concurrent streams; access to YouTube Red original programming; and support for Android; iOS; Apple TV via AirPlay; and Chromecast, in addition to desktop.

Because of all the live TV options on the market today, new tools are emerging that aim to help consumers pick a streaming TV service, like Suppose.tv or Bundler, for instance. But YouTube TV’s strategy has largely been to target younger viewers – that is, those who are already spending their time watching YouTube, not traditional television.

So far, that seems to be working. Nielsen data says that half of traditional TV viewers are over 49, but more than half of YouTube TV viewership is 13 to 34 year-olds.

YouTube TV has so far declined to provide user numbers that could speak to its traction, but that could be partly because the service is still rolling out around the U.S. The company promises that more U.S. markets will go live in the future.