Security
Using cryptographic encryption methods smart contracts are protected from outside attacks. No party can change the negotiated contract terms after the contract is created. This way payments done via a smart contract are even more secure than done over a traditional banking institution. DApps utilize the same elements of the blockchain technology and as a consequence no party stores all of your data like in the traditional applications.
Efficiency
Programming a smart contract takes much less time and resources than the corresponding bureaucratic processing and phyisical contract. Companies can adopt this to save both time and money.