The idea is not totally bad, but I have come across some bad implementations.

The worst is when there is no visual progress feedback, to know where I am in the filling process.

Also for me this is worse than a single form. At some point a question comes up which I don't want to answer, eg. for privacy reasons, or you don't need to know that for the operation I'm carrying out. I have already given out info, which I'd rather not in this case, as I changed my mind on the way.

I believe that multiple page forms have a lower conversion rate, while also wasting non-converted consumer time. this adds frustration, and lowers future conversion rates. Happened to me.