UPDATE: I’m told the trio will stick around for a few months to help out with the transition. But to what? First priority is finding a replacement for CEO Miller.

Miller announced the deal in a short blog post today.

Last.fm, which provides free, ad-supported music streamed over the Web, was the first major acquisition the broadcaster made after bringing on digital M&A pro Quincy Smith, who is making plans to set up shop on his own. CBS (CBS) sends out a steady flow of press releases touting the site’s growth–the most recent one I have, from last month, pegs its audience at 30 million monthly users, while Miller’s post says they’re up to 37.3 million–but turning online eyeballs and ears into dollars has been hard for every Web music start-up, and Last.fm is no exception.

The unit saw its headcount cut significantly during CBS’s reorg of its interactive group late last year, and last month the company combined Last.fm with the online stations from its CBS radio unit.

Here’s text of the post announcing the founders’ departure:

After two years running Last.fm within CBS we feel the time is right to begin the process of handing over the reins. This is the latest stage in a long journey for us founders, which began in a living room in East London in 2002, and took us to the headquarters of one of the biggest media companies in the world.

It’s been a privilege working with the incredible team here in our London office, and we’re extremely proud of what we’ve achieved together. Last.fm’s users have more than doubled in the last 12 months (we are now at an all-time high of 37.3M monthly unique visitors), and we’re confident the site will continue to go from strength to strength. Being a part of CBS, and the recently formed CBSi music group, continues to open up many opportunities for Last.fm. Recent product releases such as the new visual radio, and the Last.fm on XBox announcement, are an indication of how much more Last.fm will achieve.

A huge “Thank You!” has to be said to all of you in front of your computers. With your contribution, enthusiasm and scrobbles you have helped to make Last.fm into what it is today: the best place for music online. Big up yourself for that, as we say here in East London.

That’s all folks, we are going to miss you!

CBS paid $1.8 billion for CNET last summer, and today it is dealing with the consequences: A re-org and layoffs.

CBS execs won’t release specifics on the firings and won’t say how many people were let go altogether. So news will be coming out in piecemeal fashion for some time.

The best that I can tell, though, the cuts came throughout the company’s interactive group, from its London-based last.fm radio service through CBS (CBS) headquarters in New York to CNET’s homebase in San Francisco.

Based on the fact that CBS Interactive boss Quincy Smith flew to the west coast to quarterback the re-org this morning–and the fact that CNET was much, much bigger than the CBS Interactive group–I’m assuming that more CNET employees were let go than anyone else.

Quincy, if I’m wrong, please let me know. And CBS Interactive/CNET employees can reach me directly at peter@allthingsd.com.

In the meantime, here’s the new structure of Smith’s group, via an internal memo that comes from him and Neil Ashe, his CNET counterpart:

Team,

As we come to the end of 2008, we have a lot to be proud of. CBS Interactive is the best online content network for information and entertainment. Our properties are expanding, advertisers are capitalizing on our properties and their scale, and we are positioned well to continue to grow. As we prepare for 2009 and beyond, we’d like to update you on this progress, announce some organizational changes and comment on the broader market environment and how it impacts CBS Interactive.

Progress

CBS Interactive is the 8th largest Internet network in the world. Our combined traffic is up nearly 30% since we closed the merger this summer. CNET, CBSSports.com, BNET, GameSpot, TV.com, CBS.com, last.fm, and CHOW have each had record traffic within the past three months. Our commitment to our users is paying off.

Advertisers have noticed. We have recently signed and announced deals across several of our properties with Microsoft, AT&T, Intel, Bertolli, EA, and GM. In these challenging economic times, marketers are consolidating their efforts with their best partners. Our properties, our audiences, our ideas and our insights will continue to differentiate us in the marketplace.

Finally, we have contributed to and benefited from the TV and Radio divisions of CBS. We’ve done nearly 1,500 purpose-driven promotions to our properties on Broadcast TV, Radio and local TV Stations; CHOW and GameSpot content is running on the CBS Outernet; and CNET ran a major consumer campaign in markets like New York and San Francisco through CBS Outdoor. CBS Interactive is also a key partner to CBS Television Network for major broadcast events. In just the last week, we featured complementary content for events including The Victoria’s Secret Fashion Show, the Grammy Nominations and the SEC Championship.

Moving forward, we have a lot to look forward to. Events like CES, The Grammys, and March Madness on Demand are all just around the corner. Each represent huge cross-platform opportunities where CBS Interactive will again help complete the experience with coverage on air, online, and on mobile for our audiences.

Organizational Promotions and Changes

As we enter 2009, we are making some changes to our organizational structure to capitalize on audience and advertiser overlaps. We are also making some changes to key functions so that we can realize the benefits of our position in the marketplace. These changes mark another significant milestone in our integration, as we fine-tune our organization to best take advantage of the power of our entire network.

Sports, Games and Music

We are combining our Sports, Games and Music properties into a single group led by Steve Snyder. Steve has tremendous product and leadership experience and an enthusiasm for each of these categories. In addition, Tom Jones will be moving over from CNET to head-up the sales efforts for this group. Within the group, our talented senior leaders including Jason Kint, Rich Calacci, Jaci Hays, Kevin Menard, Felix Miller, Doug Schmidt and others will report to Steve and to Tom.

Entertainment & Lifestyle

We are also moving our Lifestyle properties, CHOW and UrbanBaby, to the Entertainment group (TV.com, CBS.com, The CBS Audience Network and TheInsider.com) to capitalize on the similarities in audience and advertisers. This group will continue to be led by Anthony Soohoo with sales led by Ken Lagana. We’re excited to see the innovation that will come from this group in 2009.

Technology & News

Under the continued leadership of Joe Gillespie, our Technology & News division will bring CBSNews.com and CNET News.com into a single CBS Interactive News Group. Each site will maintain its own brand identity, while benefiting from shared resources in design, product and engineering to deliver deeper and more comprehensive coverage of major stories and events. Led by Mark Larkin, with Dan Farber as Editor-in-Chief, CBS News.com and CNET News.com will also have the opportunity to share content and collaborate on stories for the benefit of their unique audiences.

CBS Interactive Marketing

We are bringing together our key marketing functions into a new group called CBS Interactive Marketing led by Mickey Wilson. The group brings together expertise from across the organization so that we can capitalize on our biggest opportunities, and elevate the company to be a strategic marketing partner whose products, consumer insights, and ad innovations are critical to our clients’ long-term success. They will establish the company as the standard for premium content online, and define and evolve brand strategies to capture the biggest opportunities for audience and revenue growth through market planning, insights and execution.

CBS Interactive Business Development

We are also bringing together all of our business development activities. This group will be led by Mike Marquez. Mike and his team will be responsible for the development of all new partnerships, investments, and acquisitions. They will be charged with taking advantage of knowledge sharing across the whole company to ensure that we are the strategic partner of choice for the industry.

Market Conditions

As you know the general economic environment continues to be a challenge. We have always been very aggressive about managing our costs, and that requirement is even more critical now than it has ever been. We believe this new, more efficient organizational structure will produce better results for CBS Interactive, and also result in lower operating costs. It is always very difficult to make these kinds of reductions, but they come after a thorough review of how we are organized and how we operate, and what best serves our many users, advertisers and employees.

CBS Interactive is a special place because of you, and we thank each of you for what you have done, are doing, and will do to exceed the expectations of the tens of millions of people who come to our properties every day.

Today, we sit in a great position. People seek out our brands because we provide them with the information and entertainment they want and need, and marketers seek us out because of the powerful audiences we attract. We are positioned to grow in 2009 and beyond.

Best,
-q, NA