You've written your book. You've found a large or small publisher or have self-published. You've found a few or maybe many readers but what do you need to do to keep them interested in the book and to come back when you've written another?
The first thing is to know your reader. If you're writing for a literary audience, then you need to know what interests them. If you're writing for readers of popular fiction you need to know the audience. Your success or failure lies on how you choose to follow your knowledge of what interests people. I've some friends who write what I consider literary fiction and they try to cram it into the popular fiction category. There are some readers who read both kind and enjoy both. But if you're writing for the wrong audience and using the tricks to interest the readers of the opposite kind of story you may find readers are few and far behind. There are also some books that appeal to a wider audience, If you manage that one, you're on your way. So look at your friends and find one who loves to read the kind of book you want to write and keep them in mind as you craft the story.
Another way to keep readers interested is to use the time element. She has twenty-four hours to find a solution. If you're using this to keep your reader interested in what comes next, remind the reader of the lapse of time. The time element doesn't have to be hours or days but could be months. But there has to be the urgency to solve the problem in a short time. The time element could be joined to a major complication or a minor one.