Some of the most profitable publishing genres are those that you would likely pick up on any day when visiting a book store. In other words, the publishing world is very depending on the standard marketplace. What consumers want is what the publisher will publish. As you search for your options in publishing, note that any genre can be a popular one in mainstream as long as the story told is unique and timely. Meet these two qualifications and your book is likely to do well.
Fiction continues to be one of the most popular of all book genres (even outside the traditional genre world) since there is an endless need to feed the imagination. From a publisher's point of view, though, this market is very saturated. Many publishers are interested in choosing already proven authors, since the risk of publishing books from them is less than publishing from an unknown author.
Within the fictional element, top published genres include science fiction, romance, realistic fiction, crime, and mystery books, but others including action adventure, fantasy and westerns do well too.
Those not interested in producing fiction will find other opportunities out there, including how to books, religious books, and financial related books. In these areas, the bestselling books come from professionals: people in the industry that have some background, and therefore are believable.
In order for there to be a market for any of the most popular genres in publishing, there has to be an interest from the general public. This often starts with an understanding of the market. For example, in a slow economy, books on saving money and being frugal will do well. This is particular important in the nonfiction elements.
The popularity of books that are completely out of the normal range continues to grow, too. For example, the Harry Potter series shows how a unique world can capture the hearts and imaginations of millions. The key here is that the books were something completely different than others within their genre. Plus, their well written style attracted both a children's market and an adult following, which pushed them to the top of the most wanted list.
The most popular publishing genres are often something that change frequently. If you are a new writer looking for a profit, contact the publishers and find out what they are looking for. Most publishers have a list of wanted titles or topics, and some will even pay you to write them. Since the research has been done on these topics, a well written piece is sure to be one the publisher is going to be interested in. Publishers do extensive research on market trends to know whether any book will do well, no matter if you bring that book to them, or they bring that book topic to you.