In fact, the game does offer a limited form of progression comparable with its contemporaries in related genres. (mmobro.com)
Click on the genre that fits your book best, and it will take you to a page with related genres in the upper right hand corner. (writingbytheseatofmypants.com)
Basically, keep writing in one genre, or at least related genres so you get crossover between customers. (thecreativepenn.com)