But there is causation - first rights are gone. I doubt there are solid stats on this but from what I see agents and publishers saying, I stand by my post.
You can stand by it, but it's provably wrong. You made a categorical statement. You don't need stats to disprove it, you just need a single event that doesn't conform. I know people personally who have traditional contracts for books that were self-published and didn't sell well when self-published. In speaking to agents about this, what I've been told is that for some publishers that kills your chances, and for some it doesn't. For your statement to be true, then you'd have to find me a book that no traditional publisher whatsoever will take, but that otherwise would have been taken had it not been self-published. You are overstating the case, using an outdated view of the publishing environment. It's just not true anymore no matter how long you decide to stand by it.
I'm sorry but you're very much missing the point. The point isn't that 'self-published' (which included posted in full for free) work cannot be traditionally published, it's that in general terms it reduces your chances. You say 'some publishers don't like it' as if that's not a huge problem in selling a book. There are what ten or so publishing houses that really matter, right? If my posting my work online means that one of those publishers won't even take the call that's a major decrease in the chances for that work to be published. It doesn't matter that some people manage to make the jump, what matters is that today I am better served by keeping my work to myself when seeking traditional publishing. That's just the way it is. And yes, that makes seeking critique substantially harder than it should ever need to be and that's bullshit by itself. But of course I'm going to pursue my best interests. I'm not going to post up all my work a defy the industry to do something about it. I want to get published. I'm going to do what gives me the best chances of that.
Are you misreading my post perhaps? By far the likeliest scenario is that by publishing your whole book on the web in any form, you destroy any chance of a traditional publisher being interested in it. For every example you can give of a SPed book that was then trad published, I can find you an agent saying "I can't sell SPed books." I know I'm not going to be swayed by your examples and I don't think you'll be swayed by mine, so I don't see much point in discussing it. I just know that I would never post more than about 5% of anything online if I wanted to trad publish it, and that's what I'd advise other writers who asked my opinion. I'm sure they'll research it and come to their own conclusions.
Just out of curiosity, when your agent took you on, did she ask you if you had published your book online at all?
Yes. When signing the contract she pointed out the part that said I confirm it's all my own work and hasn't been previously published.
I wonder what would have happened if you'd said 'yes, I put some of it online?' She'd obviously got you to the point of signing the contract, so I wonder if that all would have changed if you'd said yes. It might be a hypothetical question to ask her, if you ever get a chance. Would that have been a deal breaker?
It'd depend on how much "some". Like, 2k-ish words of it are online (right here in the forum) but I'm 100% sure no publisher would care about that. The whole thing? I'm equally sure she'd have told me "I can't sell it then, idiot! Write me something new!" Maybe without the idiot part. I can ask her. She's still doing that interview for me.
It's a good question, because of all the swapping of stuff people do online. I have seen blogs where people run stories in installments as well. Just curious how your agent would view this kind of thing. (As opposed to self-published stuff up on Amazon for sale, etc.) Would it be an absolute 'no' or would there be some kind of degree of publishing that would be required for 'no.' Keeping in mind that she'd already accepted you as a client.
@LostThePlot I don't think there are any questions about whether it reduces chances. It has to, because some publishers won't consider it. But it doesn't eliminate them.