In terms of interchange formats these are quite popular/common: EDI (serialized as text or binary), CSV, XML, ASN.1, and JSON are extremely popular.
I 100% assure everyone reading that their personal information was transmitted as CSV at least once in the last week; but once is a very low estimate.
Not because they use CSV's but because, as an industry, they have not figured out how to reliably create, exchange, and parse well-formed CSV's.