What do book publishers look for in writers?

[James]

[662]

Someone who can sell product.

It's about money. You sell product, they like you.

[Anna D]

The ability to write marketable books.

[David]

What do you think they look for James? Publishing is a business. If it's a cooperation, they have shareholders. It's all about selling books and making money.
That said, agents love to read good new ideas. Sometimes these poor people are portrayed as heartless dream killers. In reality, agents are nice people who would love to be the one to discover a fresh new writer.

[agilebrit]

First and foremost, you have to be able to write a book they think they can sell.

They like a professional attitude. If they suggest a change, they don't want an author who would throw a tantrum about it. They like it if you can hit your deadlines. They like people who can self-promote and who are open and accessible to readers via social media.

But mostly, they want a product they can sell. I don't know why the other answers got thumbs-downed, because they're true.