Read MoreRupert Murdoch and Masayoshi Son triggered M&A shockwave
Some TV executives argue that mergers could help the advertising problem. So far, only a few companies have made strong efforts to sell advertising-supported digital video. Hulu, which was controversial before advertisers began to embrace video ads, now appears to be working very well for its owners (CNBC parent Comcast, Disney, and 21st Century Fox). Discovery Communications also recently made a deal to provide some content to Hulu.
There could be a scramble to get in front of digital-video advertisers in the next couple of years, and scale would offer advantages. One issue is dealing with the complication of a quickly evolving industry: Unlike TV, which relies generally on Nielsen ratings, various ad agencies use different metrics to measure video impressions. Larger companies can probably juggle the challenge more adeptly, executives say.
There's also the issue of getting the attention of advertisers that are focused on deals with big content companies. In the spring, the likes of Google and Yahoo will meet with advertisers at the so-called digital upfronts just before TV companies hold similar meetings. While major TV content companies will get digital meetings, it's not clear that smaller TV content companies will be able to lock those meetings down, according to advertising executives.
Any new pressure to merge from the advertising world would come on top of worries about cable and satellite companies getting too powerful. A range of industry players have been touting the merits of content company M&A after the proposed mergers between Comcast and Time Warner Cable along with AT&T and DirecTV (both of those deals remain under regulatory review). The thinking is that content owners need scale for leverage in negotiations with the cable and satellite companies that buy their product.
Indeed, plenty of deal talk happened in 2014 but nothing significant was consummated. Time Warner CEO Jeff Bewkes met with 21st Century Fox CEO Rupert Murdoch at the Allen & Company conference in Sun Valley, Idaho, in early July to discuss a deal. Murdoch later made his wishes public but the companies couldn't agree on a price and he walked away.
Premium cable network Starz, which generates revenue from customer subscription fees rather than advertisements, had talks with a number of potential suitors in 2014, according to people familiar with the matter. Starz declined to comment.
Which companies are the most likely merger candidates in 2015? One pair that are often mentioned by investors as merger candidates (though not necessarily with each other) are Viacom and CBS. But until the advent of the post-Sumner Redstone era most agree nothing is likely to happen. The 91-year-old Redstone is chairman of both companies.
More realistically, medium-sized content companies could get the most out of mergers, investment bankers say. Some potential targets include Discovery and Scripps Networks Interactive. Discovery and Scripps declined to comment.
But even for those companies, the benefits of a merger look limited. In recent years, cable and satellite companies have argued that many content partners offer too many channels that have a small number of viewers.
Discovery, for instance, operates 13 national networks in the U.S., but a small number of them are the ones that really count: Its namesake Discovery Channel TLC, and Animal Planet account for 70 percent of its domestic network revenue, according the company's most recent annual report. The remaining channels are smaller and probably wouldn't help much in carriage negotiations.
Any boost to Discovery's U.S. operations would only go so far. Discovery depends increasingly on Europe after a series of acquisitions in the last few years. In the third quarter, the international networks segment generated $818 million in revenue, or 52 percent of the companywide total. That's also worrisome given that many European economies have been slower to recover than the U.S.
Scripps is in a different boat, with six domestic networks and a tiny fraction of its revenue generated overseas. That means any improvement in the domestic business would have a bigger impact on its profits.
Despite weak stock performances in 2014, content companies don't look cheap just yet. Scripps is up 80 percent since the start of 2012 and Discovery is up 68 percent.
Assuming the big cable mergers get approval and advertising stays weak in 2015, M&A chatter may only get louder in coming months. And if conditions get tough enough, a couple of deals may actually get done.