Q: What about two-book deals? How finished does a sequel or tie-in need to be and how likely is it that a debut author can get one?There are great reasons to sell a book in a two-book or multi-book deal:
* You get a guaranteed next book for the same amount of money, even if the first book just does "meh".
* You get more time for the publisher to "build" you -- if they've made an investment of time and money, they are expressing faith in your future and longevity, and the hope and expectation is that they will try to make sure that you do well enough for them to make some dough, at least.
* There is a sense of security that comes with knowing that this book is sold already. Some authors thrive with this knowledge. And some authors work best under a deadline.
There are great reasons NOT to go for a multi-book deal:
* You are locked in to having sold the second book for the same amount of money, even if the first book does phenomenally well. You may deserve a lot more money for book two, but the book is already sold.
* If you don't get along with the publisher, or don't agree with how they are handling your career, or think the book is being published badly... you are stuck for another book, with an potentially expensive and hassle-filled nightmare if you want to get out of the contract.
* There is a sense of excitement and freedom knowing that you don't have a contract for the next book. You could do anything you want! Some authors work better if they "stay hungry" and free in this fashion. And some authors panic under a deadline.
Maybe half of the deals I make are multi-book deals, and many of my debut novelists sold in a multibook deal. Sometimes these are series or sequels, though just as often book 2 is an entirely new book. Whether we go in the multi-book direction depends on the author, the book, the desire of the publisher, if the book lends itself to a series or sequel, if there is competition, etc.
The good news is, the most I've ever had at this stage is a paragraph or brief synopsis describing what book 2 might be. In some cases, in fact, I have had absolutely nothing, but the publisher was ready to make a commitment to the author even without an idea for book 2.
As in so many aspects of this business, there is no one-size-fits-all answer. This is something to discuss with your agent or editor when the time comes.