I found the answer to a question that had bothered me for five years and just want to share it with you. So, how do you find out when demand in your niche will start to rise, when there will be a peak, and when it will fade? Smooth out the BSR curves for winning books in your niche and layer them over each other - you will see a clear picture. Unbelievably simple when you see it, but it took so much time to find this idea.