You probably already know this, but it doesn't hurt to post it here just in case you don't. Plus, it might help others who are new to the publishing world.
Keep a close eye out for the non-compete clause in the contract. If it's there - and the Big 6 love to include them - make sure it's something you can live with or something you can negotiate so it doesn't impact your other writing. I've seen other writers turn down a contract with a Big 6 publisher because their contracts included clauses that tried to restrict them from selling anything elsewhere.
Originally Posted by Edward M. Grant
So they have massive marketing power, they're going to have 'shelves of the book in all book shops'... and they're only offering a $5,000 advance?
Does not compute.
Advances are down everywhere, Edward, as are print runs unless you're already a Very Big Name.