Why don't Verizon, Sprint and other CDMA networks in the USA not use R-UIM? I know it's used in CDMA networks outside of the USA. For a while Sprint and Verizon were selling Nokia phones with a place for a R-UIM.
Cause they are lazy and there is no benefit for them? They don't want you to be able to switch around phones between carriers like most of the world does. They want to sell you their phone.
CDMA carriers are slowly migrating to UMTS. there is no incentive for them to switch to RUIM based cdma when cdma is a dead end technology, everyone would rather go to UMTS / HSPA and they not only benefit from a sim card, but high speed data and more that is not available on cdma.