From what I understand, the treatment phase is long. Especially if you have color! There are certain colors that may take 3-6 extra treatments. I think one of those colors was blue, but don't quote me on that one. I'm remembering from a tv show I saw on TLC. I recall that the treatments tend to take 8-15 sessions to fade a tattoo to the point of not seeing it.
I have to ask, though... since you did get the tat in the first place, would you consider the following? Now that the original is faded, you could put another (different and better) tattoo on to cover what's left of the old one. Unless, of course, you've changed your mind about the location. There are several artists that are very skillful in the art of the cover-up. I know of a couple in the Chicago area if you're by me. And if you're not by me, I could ask my artist about other artists in your area.