Can a news site become a TV network? Or a radio station? Or if it can’t become one, can it at least grow to include one?

These aren’t theoretical questions, as Monday saw the launch of HuffPost Live, the new streaming TV-style video network from The Huffington Post, and RadioBDC, an alternative streaming radio station from Boston.com, the webbier side of The Boston Globe.

The launch of two media-jumping online ventures is likely a coincidence — though getting clear of the Olympics was probably a motivator for each — but they share many commonalities and the same goals. On their first day, both gave early indications of what they see as their strategy for success. Both Boston.com and The Huffington Post want to use digital distribution to offer something like a traditional broadcast product, but at a much lower cost than what starting a TV network or radio station ran pre-Internet. They both also want a shot at a new channel of advertising dollars to complement the display-heavy advertising they rely on with their main products. In order for both to work they’ll need to find, maintain, and grow an audience and advertisers. On launch day, HuffPost Live counted Cadillac and Verizon as their “founding partners” for the network. On RadioBDC, launch advertisers include Miller/Coors, Anheuser Busch, and Comcast, a spokeswoman told me.

HuffPost Live, the latest spinoff of Arianna Huffington’s media empire, is an attempt at merging live TV with the expediency and interconnectedness of the web — to get the engagement promised by second-screen visions of television watching by building for the web from the start. HuffPost Live promises 12 hours of live weekday programming that combines hosted segments and audience contributions. “With HuffPost Live, you’re invited to be part of a different kind of conversation, whoever you are, wherever you are,” Arianna herself said in the network’s opening minutes.

But while the medium may be shifting, a lot of the content looked familiar. On day one, HuffPost Live had many of the familiar trappings of cable news: a well appointed studio, handsome hosts, and various treatments on the day’s news. But instead of Wolf Blitzer barking at reporters and pundits in the Situation Room, HuffPost Live relied on Google Hangouts. Monday’s first segment, a roundtable on Mitt Romney’s pick of Paul Ryan as his running mate, featured a diverse cast of contributors live from their bedrooms/guest rooms/home offices. As novel as that was, the guests still fit into familiar archetypes: a conservative, a liberal, a knowledgeable reporter, and an everyman. That seems to be the model for HuffPost Live, as a segment later in the day on home foreclosures featured Huffington, the head of a mortgage-resolution organization, actor John Cusack (!), and a California man struggling to keep his home.

Of course, HuffPost isn’t the only one investing in live video. The advertising dollars are typically better than in traditional web display advertising; as Raju Nasrietti of The Wall Street Journal told us in June: “We are sold out. There is no shortage of demand to generate more video views.”

HuffPost Live wants to differentiate itself from other online video in terms of its content and its “live-ness.” The segments are like taking a dive into different HuffPost verticals — politics one minute, entertainment the next, technology later. (No sideboob yet.) But what sets it apart is the audience experience: The interface features a video player on the left, a comment stream on the right, and a big red “Join This Segment” button. A module above the video player lets the audience keep tabs on what stories and segments are coming down the pike, like the left rail on ESPN’s SportsCenter.

Boston.com’s move into radio

The strategy at Boston.com’s RadioBDC also seems to borrow a lot from its terrestrial peers. The streaming station is an ambitious project for Boston.com, which scooped up the on-air talent from Boston’s WFNX shortly after the station’s frequency was purchased by Clear Channel. As far as new ventures go, RadioBDC will stick closely to the traditional radio format, broadcasting 24 hours a day, with DJs on air from 7 a.m. to 10 p.m. At noon Monday, on-air host Julie Kramer kicked-off the launch with an appropriately titled show, “Lunch at Your Desk,” and it sounded a lot like you’d expect an alternative radio station to sound.

With no terrestrial signal, that desktop crowd, along with the mobile crowd, will be RadioBDC’s main audience. They’ve already launched apps for iPhone and Android, but the power of Boston.com promotion will likely be key. The site is always among the most visited regional news sites with over 6 million uniques a month. RadioBDC has its own page under the Boston.com umbrella, but it also receives prime billing on Boston.com’s homepage, with a banner ad and button to launch the radio player as well as a widget near the top of the page.

By default, RadioBDC pops out into a separate window, making it meant for hanging out in the background during the work day. If you’re the type of person that wants to hear Elvis Costello, Weezer, or R.E.M while you work, you can now hear the music you love while clicking through Red Sox news or updates on the Massachusetts senate race. For Boston.com, that potentially means exposing the audience to double the ads, on the site as well as on the radio stream. Lisa DeSisto, general manager of Boston.com, said over email that “streaming spots are just one component of the marketing packages which include digital assets, event sponsorships, social media tie-ins, and promotions.”

HuffPost Live also seems designed for the specific purpose of keeping the audience around, either to keep tabs on what’s being talked about in comments or to contribute to an upcoming story. HuffPost also wouldn’t mind if you kept it open in a tab all day and popped in from time to time.

While they share a launch date, RadioBDC and HuffPost Live operate at different scales: RadioBDC has a handful of people on staff, HuffPost Live hired around 100 people for the launch. Success will look different for the two entities. But they’re both counting on a similar audience: the bored-at-work crowd, desk jockeys looking for something other than an Excel spreadsheet to pay attention to. Considering how much time we spend tethered to our computers this strategy makes a lot of sense. Individually our stray, off-task web surfing may not amount to much, but HuffPost and Boston.com are hoping that, collectively, it adds up to many millions of hours. TV and radio originally brought the news and music live into people’s living rooms. Now HuffPost and Boston.com want to bring news and music live to your computer, tablet, or phone during the day, probably at work. Think of it as the earbud audience.