You need to read your genre before you start writing. Yes, really. This is true whether you plan to publish traditionally or go indie. If you don’t read books in your genre, you are going to have a hard time marketing effectively. You won’t know the general parameters of the genre, and therefore you won’t know when you are stepping outside of the genre. (I am all for risk-taking, but you need to understand that it IS a risk, and not just be making a choice out of ignorance.)
Let’s say you’ve written a contemporary romance, but haven’t ever read one. How do you determine if your book is long enough? How do you know if your story is marketable to romance readers? You might waste a lot of time querying agents and editors who aren’t right for your book, because while you call it a contemporary romance, it might actually be chick lit, or a cozy mystery. If you don’t read, you can’t properly classify it. And since agents and acquiring editors usually specialize, you should make sure you are targeting ones that are right for your book.
“But I’m planning on self-publishing,” you say. “So labels don’t matter.” Okay, how do you know what type of cover you’d like? If you don’t read your genre, you don’t know your market, and are going to have a tough time attempting to reach that market.
If someone said to you, “I’ve never eaten cake before. But I knew it couldn’t be that hard, so I made one. Now I’m going to make tons of money selling them on the internet.” Sound crazy? That’s because it is.
Of course, there are exceptions to every rule. Best to assume you aren’t one of them.