The short answer is that RBF is a mechanism to update a transaction that is not getting confirmed by miners because its fee is too low – the idea is to increase the fee to give miners an incentive to mine it.
Try to think of services that had a hard time being monetized or that were primarily consumed by other computers. RSS feeds. Community databases. Niche search sites. Networks of sensor information. In each of these cases, a computer with a 21 account can pay satoshis for each query or visit. Multiply that times millions of devices and you start to have a functioning system of value for value: a machine payable economy.
As a starting point, we built Edgecoin, a private cryptocurrency ledger that maintains a secure, independently verifiable record of when one of our founders or advisors has signaled when we should be spending time with another seed-stage founder.