Like most media companies, CBS owns a variety of assets, including the CBS TV network, Showtime, a production studio, some digital assets, a stake in the CW network, owned-and-operated local TV stations and some other cable channels.
It's a jewel for a large company that wants content, such as AT&T. CBS owns the rights to highly rated sports such as the National Football League and has consistently been "America's most watched network," leaning on hit shows such as "The Big Bang Theory" and "60 Minutes."
But AT&T just completed its $85 billion deal for Time Warner, and that acquisition is still being appealed by the Department of Justice on antitrust grounds. The Time Warner integration will be priority No. 1 for AT&T -- assuming no further regulatory hurdles.
Verizon has said repeatedly it isn't looking to buy a big media company.
Comcast loves NBCUniversal, but there's no way regulators would allow a company to own both CBS and NBC.
Disney is similarly out as an acquirer, as it owns ABC. Plus Disney just bought the bulk of Fox's assets and will need to integrate those first. The new Fox will also be subscale but again won't be able to put CBS and Fox under the same ownership.
Regulators won't allow a foreign buyer to control CBS.
Charter Communications, the second-largest U.S. cable company, doesn't own a media entity and could be a buyer, but CEO Tom Rutledge has expressed more interest in buying other cable companies, should they come available, rather than spending big bucks on content.
Technology companies still haven't taken the plunge to own content. Netflix's entire strategy is predicated on putting media companies like Showtime out of business, and Netflix is consciously staying away from live programming.
Amazon, Apple or Google all have the money to buy CBS, but all three companies have had opportunities to purchase legacy media in the past and all have passed. According to Greenfield, that suggests they're looking to follow Netflix's plan to build internally rather than buy externally.
"We simply do not see a buyer for CBS beyond Viacom, which is why it would make sense for CBS to proactively propose a Viacom transaction sooner than later as scale is becoming increasingly critical in the media industry," Greenfield wrote in a note to clients.