I like to think it’s possible to do both. For instance while working on the plot for my next paranormal romance I discovered that books with vampires or werewolves sell better. My book was about shape shifters, but not werewolves. I wondered if I should try to come up with a different plot, but then it dawned on me. With just a little twist the book could be even better and the titled changed from Shifting Affections, to Enemy of the Wolf. Fingers crossed that the editor likes the changes, because she liked the original idea.
If you’re going to get published today, I think you have to think about the money, too. For example what are the chances of selling a gothic novel today? Slim. Writers have to keep up with the market in order to keep selling. This is the reason James and I have been able to continue writing for thirty years. We’ve written in many different genres over the years and have had a ball doing it. I wouldn’t think it would be fun to write one type of book for thirty years. So, keep an eye on the market, it’ll be changing again.