I'm not a writer, but I sympathise with your plight. I think you'll find that you're not alone - the internet is full of unknown writers trying to break on through to somebody... anybody! And ultimately that's the problem, there's no way that I can filter your book from any other, and that's why the self-publishing route is a hard one and, I think, a dead end for all but the lucky or well connected few. Why is anybody going to read an unknown writer online, when most avid readers have piles of unread books in their homes just waiting to be read (I know I do). It's not an insult to you and others like you, but I see absolutely no incentive to do so (also I refuse to read anything but the shortest of fictions on a screen because I'm a technophobe).
As things stand I think the only people who might read your book might be other aspiring authors who would probably expect the same courtesy in return, which might not be a bad idea, but I'm not sure that this will really help you break through to a general readership or not.
Saying that, I think there are online routes to an audience - via short stories and flash fiction. People are far more likely to read this stuff, especially if its on an online magazine with an editor that they trust. From there you might get some interest in your longer work or from there maybe you could try an anthology or print magazine or two...
A friend of mine who writes ghost stories had a interesting way of releasing his stuff. In the early 00s he recorded audio book versions (hiring narrators and studio time) and sold CD-R collections of his tales for over ten years. I'm not saying that he made a living using this method, but he sold about a thousand different CDs over about ten years making a small profit), which isn't bad going for an unknown. He has since released a few PoD books via Lulu and been printed in a couple of print and online anthologies (in fairness, I think he should have tried submitting to magazines and the like many years before hand). Admittedly that was ghost stories, which kind of suits an aural tradition (round the camp fire), but maybe a variant of it might still work with podcasts and the like, as I don't think the CD-R route would work today.
But I think you're right - just putting out an eBook and pimping it on a few forums won't do a thing. There's just too many bad eBooks by hopeless hopefuls already and there is no way to distinguish the one in a million gem from the rest of the crowd.
All I would say is: make sure that if you are asking money for a product that it is worth the money - especially if it's a novel. A long time ago I had a lil review blog and someone sent me their self-published fantasy novel and, frankly, it wasn't fit for purpose. It read like a first draft (if that!), it showed no signs of being copy edited and it was a slapdash affair! (although it had a nice cover) It was the poorest written thing I have ever read (I could only read two chapters) and since then I have been very suspicious of all self-published work. I refused to review it for him, saying that it wasn't my tastes (I only took it on that understanding). So, make sure that it's a professional standard! If I had paid money for it I'd have given it a one star review on Amazon and anywhere else with no qualms as there are enough poor books out there already. (btw he'd managed to get a big selling author to write him a testimonial - maybe a tactic you could try?) Even those 50 Shades books had been copy edited before being published. It is an essential process and there are not many books professionally published that aren't copy edited. I imagine very few self-published authors bother. Even if your eBook is free, I think it needs to be treated as if it was being paid for, as, after all, reading costs the reader their precious time, so you need to treat them with every respect.
Anyway, I'm sure there will be many giving their opinions on this subject with more knowledge than me.
I wish you luck.
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3. a public meeting place for open discussion