I have a thought on this. Let me set the scene by spending a paragraph reminding us of what we already know. Complaining about control of most of the media by corporate conservatives is just whining. Yeah we have our share of blogs and web sites, and web casting, and pod casting, and alternative radio and (for the moment anyway) public access TV, and e-mail lists , and progessive magazines
-- of varying quality. But those are marginal compared to the mainstream networks and cable stations. I remember when Liza got on one of the mainstream shows, someone commented that showed how we can get access if we are stylish enough. But you may have noticed just how often Liza gets those invitaions. Of course she a bit a busy to accept them right now, but the point is the offers to appear on CNN and ABC are not just pouring in.
One more point we already know; monoply is not the main problem; advertiser support media is the main problem. True when there was more media diversity, there more occasional cracks a left viewpoint could slip through now and again. But ultimately an advertiser supported media means the advertiser is the customer, the view/reader/listener/whatever is the product, and the media itself is nothing more than bait. That is going to affect the quality, reliability and diversity of information regardless of ownership.
(Also monopoly is at least in part a side effect of advertising. There are virtually no limits to economies of scale in advertiser supported media. If your advertiser want a mass audience, then the larger the beter; if advertiser want to narrowcast, they would rather deal with one business entity that has a large variety of products reaching a large variety of consumers so that they have on stop shopping for their target audience of the week.)
So it would not be a bad thing to have a demand that confronts this straight on. Let me suggest such a demand: a tax on advertising, marketing, a public relations (including "enhanced sponsorship" of public broadcasting), the revenue from that tax used to finance vouchers divided equally among the population of the U.S. - those vouchers good for purchase of any media that is purely subscriber supported.
There are a number of good things about such a demand. One is that it is educational; it helps highlight how advertising/PR helps warp and distort media. It emphasizes on an emotional level how conventional media makes ordinary people the product.
Another is that it is appealing. You are proposing to tax something that is normally hated - advertising, and then using to money to give people access to free education or entertainment as they wish. It is "free ice cream" rather than "eat your spinach". It is the reverse of most "sin taxes" The "sin" being taxed (advertising) is one that is almost entirely practiced by owners not workers. And the revenue is specifcally earmarked for one of lifes minor pleasures rather than some drab duty.
Another is that is scalable. It would be productive at even the local level. You could pass a law like this in a municipality - affecting mainly local advertising (probably there is a hell of a lot you could not touch, but you could at least hit something). At a state level you could hit a great deal more - again having huge numbers of things federal pre-emption would prevent you from touching. Still even a little bit would a useful thing.
Another is that it would be good policy if you could win it. Yeah given vouchers with no advertising as the only restriction, most of the money would not go to intentionally political stuff. Much of it would buy premium cable, or webcasts, or comic books, or perhaps porn or sports magazines - though even there I think the lack of need for advertiser would produce better quality. But some of the vouchers would go to support left media - and given what we do with essentially nothing, I'm betting we would produce some amazing stuff with even a tiny percent of what such a voucher system would offer.
And the fact that it has educational, emotional and propaganda value, that it is useful to a media activism movement even before you win, gives you a tiny chance of winning.