How to Promote a Publishing Concept?

Anything can work if you do it right. But I am hugely skeptical about round robin techniques creating a book that a non-involved reader would want to read. It tends to be fun to do, but lackluster in outcome and sales potential unless it is in some super-hot fandom zone.

Or the authors are well-known and can sell the project on name recognition alone.

Reading the page, I don't get the feeling that the project has a solid business plan. There's no talk of what rights will be required and money is not discussed in detail (it's also downplayed, by saying writers have other reasons to write... which often gets used as a weapon when people complain about non-payment, so it's a bit of a red flag.)

I think it also misses the market. My experiences of collaborative writing have gone two ways: 1) The story is like a giant cliche sundae, with extra trope sauce on top, written in a very average style. No one wants to be too radical, so that everyone can take part and the story is coherent. 2) Everyone tries to outdo each other for how ridiculous they can be, so the story makes no sense and is generally not a fun read. But it was fun for the people writing it.

People are going to drift towards option one in this case, because they're trying to put together a serious novel. So dissing other novels for being unoriginal, and dissing certain tropes, is not wise. The people who like these things will likely be writing your book for you. If they want to do something that's amazingly different, they're not going to fit in a collaborative writing project. Their chapters would stand out as too different.

So I think the first step is to market the page at the audience. Don't diss genres and tropes. Keep the emphasis on people being able to make the choices, not on whether those choices will be original (because they probably won't be). Give business information on rights, proposed payment splits and how the books will be marketed (because the best market is going to be the unoriginal sundae in this year's hot genre, not the genre-bending surrealist piece, and the campaign currently implies they think the reverse is true). It won't guarantee that people will be interested, but it would at least not put people off unnecessarily and give them the information they need to decide.

And apparently the parts that make it into the actual book will be chosen by the voting public readers. Shades of the vote-mongering mess that was the original Authonomy:
"You back me, and I'll back you."
"You didn't back me, you lying swine!"
"I'm going to vote down everything you ever write! Ever!"

Although, if prompts were provided, it might make an interesting writing game or exercise. For a few friends, or a writers' group, a self-selected group that is familiar with each other, and would go into it with a general direction, or objective.

We have a thread dedicated to PubSlush in our BR&BC room.

I wouldn't bother with it.

If your friend wants to join AW and ask for her own advice then she's welcome to: but I see some potential problems in you asking for her, so I'm locking this.