YianGaruga
Banned
The best solution is to better gauge demand, but even that is probably not always easy. Contracts are likely signed months before release.
Yeah that's a big issue and unless they announce everything far in advance (which would not be smart because people could skip releases to save for later ones) it's hard to actually predict demand. It's just a matter of experience, we're still in the early stages

As a rule of thumb I'd say if it's Vita and/or a "japanese" genere (JRPG/shmup/VN), add at least 20% to whatever you planned already. Don't underestimate the demand from these fans. I don't think there has been a Vita release so far that has been available for a long time, but correct me if I'm wrong.