Uphold is only required should you plan on withdrawing your VCOIN outside of IMVU.
You will need an Uphold Account if you want to convert your VCOIN into cash. Uphold is the exchange in which these transactions take place, and is our partner to link your IMVU account with for a smooth transfer.
Note that IMVU may also request its own internal security checks on large purchases of VCOIN or on suspicious usage.