What is a Niche A niche is a specialization within a particular field. For instance, if you have a book review blog your niche may be adult romance novels. This means that all the books on that site will be of the adult romance genre. Add a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment:*Name:* Email Address:* Website: Save my name, email, and website in this browser for the next time I comment.