I am, of course, talking about advances. Advances are what the publisher gives a writer on signing them up. It's not magic money, it's an advance against the royalties that the publisher is guessing you might make from the book. Until you've earned out your advance - ie the royalties you would have received exceed the money you've already had - you won't see a penny more cash. Publishing wisdom dictates that the amount paid out in the advance is roughly equivalent to what they'll spend on marketing: expensive books get big marketing campaigns. So you'd think that a big advance was good news (and if my publisher is reading this, they undoubtedly are) but they can be a double edged sword for a new writer.
Let's say you've got a six figure advance for a two book deal. This usually will be for the wonderful book you've written and a synopsis or outline of the fabulous book you're hoping to write next. You're thrilled, your agent is thrilled, the publisher is thrilled. You get on with writing Book No 2 while the publisher spends a lot of money on the marketing. Expectations are high. Book No 1 comes out and does quite well but you'd have to sell an awful lot of books to cover your advance and you don't sell that many. The publisher loses money. You hand over Book No 2 which you think is even better than Book No 1, but no one is thrilled any more. Book No 2 comes out with no marketing so doesn't sell (the publisher may even decide to cut their losses and not print it). Your name is forever tarred as the author who lost the publisher lots of money.
Contrast the situation with the writer who got a modest advance so Book No 1 doesn't have to sell that many copies before it starts earning out. It achieves those sales. Everybody is happy and looks forward to Book No 2, which also earns out, with sales a little bit more than Book No 1. The sales graph is on an upward curve, the author is a success and gets offered a new contract.
Over the last ten years I've met three writers who fell into the first category. None of them had got beyond Book No 2 and the advance money was long gone. They felt cheated. Bitter, even. All writing is like a high wire act, but if you have a big advance there's further to fall. Rumour has it that, with the recession, advances have got smaller and maybe that's a good thing for writers who want long term careers. Still, I can't see any writer turning down a whopping big advance. I certainly wouldn't.