Only a short while after its release, the Nintendo 3DS, the successor to the most popular handheld of all time, sold a mere 97,000 units in the US last month. That is a big deal. After all, who could have imagined just a few years ago that a new Nintendo mobile console would sell so comparatively poorly? Years into its life cycle, the Nintendo DS would sell two to three times that. It is, at the very least, surprising. The reasons for this sluggish start are many. The 3Ds’s launch lineup wasn’t spectacular. What’s more, US$249 is the highest price ever for an Ninty handheld. But with the PS Vita coming out…