You can read this book yourself, The Bestseller Code, and draw your own conclusions (it's fascinating, and it'll give you a lot of "Aha!" moments).

You can also submit your manuscript to the book's authors for an analysis on how well your book will sell. Or not. Again, you decide how true or not true this is, or how useful or not useful.

Or, you can use my summary below as a quick guideline for your daily writing, as a lot of it makes perfect sense and follows what I've been teaching here about 12 Columns, scene blocking, and style (my comments are in the parenthesis):

When I started out writing, I had no idea what POVs were out there (or even what POV meant—point of view). By instinct (and by habit, from reading other books) I chose 1st Person for my first trilogy (closest to journaling), then 3rd Person Limited for Rosehead, and so on. 

Once you pick your story's POV, you’re stuck with it, so study it to decide which one fits your story best before you start writing.