How big will self-publishing get?
Mike has written another excellent article you should read:
Over the long run, things will almost certainly change in very big ways because of the inexorable forces eroding publisher margins described above. I wouldn’t be surprised to see only two or three big trade publishers as soon as ten years from now. I’d expect that the two recent plateaus we’ve reached, with ebook sales stabilizing in relation to print and with bookstores holding their own, will prove temporary. I wouldn’t expect ebook sales or online purchasing to grow by the leaps and bounds they did a few years ago, but it would surprise me if we’ve reached any long-term limit, particularly in ebook use. (The devices keep proliferating and people get increasingly comfortable reading for a long time on screens.)
But he expects far fewer changes than many of us anticipate. It will be interesting to see what happens.