  The hype about Bitcoin has overrated the potential of smart contracts
deployed on-blockchains (on-chains) and underrated the potential of smart
contracts deployed on-Trusted Third Parties (on-TTPs). As a result, current
research and development in this field is focused mainly on smart contract
applications that use on-chain smart contracts. We argue that there is a large
class of smart contract applications where on-TTP smart contracts are a better
alternative. The problem with on-chain smart contracts is that the fully
decentralised model and indelible append-only data model followed by
blockchains introduces several engineering problems that are hard to solve. In
these situations, the inclusion of a TTP (assuming that the application can
tolerate its inconveniences) instead of a blockchain to host the smart contract
simplifies the problems and offers pragmatic solutions. The intention and
contribution of this paper is to shed some light on this issue. We use a
hypothetical use case of a car insurance application to illustrate technical
problems that are easier to solve with on-TTP smart contracts than with
on-chain smart contracts.
