Blockchain: Data Malls, Coin Economies and Keyless Payments.

We discuss several uses of blockchain (and, more generally, distributedledger) technologies outside of cryptocurrencies with a pragmatic view. Wemostly focus on three areas: the role of coin economies for what we refer to asdata malls (specialized data marketplaces); data provenance (a historicalrecord of data and its origins); and what we term keyless payments (madewithout having to know other users' cryptographic keys). We also discuss votingand other areas, and give a sizable list of academic and nonacademicreferences.