It seems that the Vita isn't exactly "backwards compatible" considering it lacks a UMD drive. Sony does have a service that is supposed to make up for it, called the "UMD Passport Program". Where Vita owners can register their old PSP UMDs and get a discounted price for the digital version from the PSN Store. Unfortunately this program will not be available outside of Japan. Meaning everyone else will have to pay full price for the digital versions off of the PSN Store.
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