Why PAF + Tiana never achieved full popularity.
It's no secret that in the Disney Princess world, Tiana is pretty low on the totem pole. While it's easy to chalk that up to the obvious, I feel as though it goes deeper.
As the father of a three year old, we try not to let her watch too much TV, but when she does, it's all about the Disney Princesses for her, and as a result, I've become very familiar with each of them, and there's one thing I can't help but notice about the ones that, let's just say aren't at the cool kids table; other than the fact that they're not of the Caucasian persuasion.
First of all, there's Mulan and Pocahantas. Referring to them as Princesses is grasping at straws, so I'll move on to Tiana and Jasmine. Whereas Cinderella, Snow White, Sleeping Beauty, Little Mermaid, Beauty and The Beast, and Tangled are set in very whimsical fairy tale settings, Princess and the Frog is not. It's set in a very realistic setting, though magic is obviously involved. What it boils down to is that like Aladdin, this isn't so much a princess movie as it is a movie with a Princess. The difference is that until recently, Aladin wasn't marketed as a princess movie, where PAF was.
The other thing is that she's a Frog for most of it. When little girls watch a princess movie, they want to see a princess, not a frog.