I'd start a business that would have offices in the top 20 major commercial cities in the world and would trade physical commodities taking advantages of the price differences between these locations. My business would use telephone or telegraph.
The presence of the internet and ensuing information exchange reduces these price differences to make such a business nonviable.
The only time you'd use a NIO client, is on a server - for example, when building a caching proxy server.
The expected benefits are higher throughput of the proxy (lower CPU/RAM consumption allows multiple clients to operate in parallel).
Individual downloads being faster was never expected to be a benefit