I used it really regularly (always diluted, because it's so much easier to work with if you mix some conditioner in) and I used to change up my color every few months-- I'd never know what I was going to dye next, not exactly, because it would depend on how well the atomic pink lifted. If it lifted really well, I'd do teal/blue. If not, purple or red or more pink. I keep my hair about as short as the person in your icon, so eventually I'd get it mostly gone or light enough to go over it, but it could be a real pain sometimes.

On the plus side, it won't fade like Manic Panic or Punky or Hot Topic's new brand. On the minus side, sometimes it will marry you.