When even a weak signal shows strengthening demand (Russia’s top search engine is Yandex, India’s first language is Hindi) merchants know that something interesting is going on, and they begin supporting new payment methods such as digital currencies. The way it works is that users accumulate or buy cryptocurrencies to use them in exchange for services, goods, and entertainment. Deposits are handled by a payments processor and are put in custody in an exchange (for instance, to engage in trading activities), vault (cold storage), or similar.
Despite the decentralized nature of the medium of exchange, there is really no implicit animosity against financial intermediaries. Business people are pragmatic, they understand that specialization breeds prosperity. As a customer your primary motivation is not to remove service providers to save a few dollars, you just happen to have a relationship with your favorite brand, not with the seller on the other side -- and you suffer great difficulties to access credit cards. As a seller, you do not want to worry about having to trust a buyer -- and settlement speed is important because even in a cashless economy, cashflows are the lifeblood of a business. As a merchant, you simply need to be able to take the form of payment that your customers are using already, and that you can exchange later into whatever legal tender is appropriate. If the payment mechanism takes care of processing and fraud simultaneously, then the decision is straightforward.
Trust asymmetries
Note that in none of those two cases were there any “real banks” involved. And these are not fictional scenarios: today there is trading between Africa and Asia denominated in bitcoin (mainly via over-the-counter markets) \cite{support}, and digital currency denominated e-commerce grows \cite{yearly} while brick and mortar retail shrinks. Money is already flowing for legitimate international commerce, largely without the banks. Figure 3 shows the intuition behind the concept.