- liquid market
- enough security for my current transfer (miners need an incentive to secure the network - and they are paid in btc)
- a price high enough that i am able to buy the amount of btc i want to transfer
For people to use bitcoin to transmit money, they need to use a service that will make it secure and very easy to use.
If this service will be popular and cheaper than the alternatives then people will use it. They will probably won't even know that bitcoin was used in the process. But this will not mean that the bitcoin "currency" will have a lot of value, because there is no reason to use bitcoin the "currency" as money.