I've got one more book left in my series of four, and then I'm switching genres. My current series is hard to define, genre-wise - it's a contemporary urban science-fiction thriller, but it's also got some soap-y elements and a lot of humor. In addition, the sci-fi elements aren't really apparent until a ways into the first book, so it seems like you're getting a more straight-forward action thriller. It's made it very hard to market, and choosing the categories on the vendor sites has been a battle.
Next up - urban fantasy. One POV character, instead of four. A bit shorter, so I can put out more than two books a year. "Simplify" is my strategy. I love my current series, and so do the few readers who manage to find it, but the business side of things has been frustrating. I've learned a lot, though, and I'm looking forward to applying what I've learned with my next series. (Which I'm incredibly excited to write, by the way - I'm not being completely mercenary in this decision.)