I have been teaching piano for a very long time. Over the years I have followed a number of different method books (Faber, Marlais, the Music Tree, Celebrate Piano), gone without a set method, and even written my own pieces. The results are always mixed - a few students progress fairly quickly - while the majority struggle through slowly - with sighs and the ready phrases - "this is hard" and "this is confusing."
It is not that my students don't like playing piano - it is the amount of effort that it takes to become musically literate that is really the challenge. Their ability to memorize the facts of the staff is quite weak and so there is a lot of struggle to move forward since the notes and intervals (bigger than a third) just aren't there - at their fingertips. (That is for a different post)
I know that as a piano teacher I am most likely only going to have my students for a fraction of the time that I really need in order to develop them into competent players. The only way I will keep most of my students playing through the adolescent years and beyond is to speed up their learning. I need to get my students sounding competent by middle school so that they can add "piano player" to their adolescent persona. I can speed up their learing using rote lessons that I create and post on YouTube.
We all know that students can play at a higher level than they can read. Rote pieces allow students to play at their playing level - not at their reading level. When a rote lesson is posted on YouTube, the actual in-person piano lesson can focus more on reading, aural skills, technique, and improvisation (to name a few possibilities), since there doesn't need to be as much time devoted to learning the repertoire on the lesson.
With an iPad or comparable device it is easy to make a recorded lesson of a piece and have students learn it from the video. I actually use these videos as make up classes for my students who cancel.
Here is a video lesson for Teresa Richert's RCM Level 2 Little Red Wagon.