I also wanted to chime in on this even though I haven't been on the forums much. I bought a NB a couple years ago I wanna say, and have used it VERY inconsistently (talking, weeks at a time of breaks, including going I think 8 months without touching it), and I have gone from a AA to a solid A that can fit into a pushup B after noogling. I had small sized domes and started filling them to the brim, so I now pump with mediums. My boobs are definitely, without a doubt, bigger with permanent growth I sustained and now that I am able to noogle consistently, I fully expect to gain probably another cup size at least in the next year.
I am 25 years old, no kids, and very very petite. I also don't take any herbs, PM, or supplements like BO. I do take MSM, silica (horsetail extract), and recently Spirulina (among other supplements not related to NBE). And I take protein shakes, but that's mostly to help me keep/gain weight as I am chronically underweight. I honestly believe that NB will work for anyone, it's just a matter of time, correct technique, and proper nutrition. Best of luck!