It IS a boost, but don?t expect much boost from it.
I placed it before the effects to boost the signal coming from the guitar, but I was disappointed when it messed up the sound coming from the distortion pedals, so I had to switch it off when playing distortion or overdrive.
When played alone with reverb, it gave a little bit of distortion that was acceptable at low volumes and is lost when you crank up the volume on the amp.
When played after the other pedals to boos their signals, it did the job pretty well. Kinda gives you a top boost for your distortion if you ever needed it. It also boosts the reverb signal so watch out for that as well.
As mentioned, I wasn?t happy with it, but I could put it to some use.