People use ZEC to transact efficiently and safely with low fees. Shielded Zcash ensures transactions remain confidential, while also giving them the option to share address and transaction information should they choose to. Private, "Z-Z" transactions appear on the public blockchain so it is known that they occurred and that fees were paid. But, the addresses, transaction amount and memo field are all encrypted and not publicly visible.
People can also use ZEC to store wealth in a hard, privacy protecting, asset. There will only ever be 21 million ZEC units, meaning that the asset has a fixed supply. Once the 21 millionth ZEC is mined into circulation, the asset will become anti-inflationary. Anti-inflationary assets are a good hedge against inflation in the event that centralized gatekeepers inflate national money supplies.
People can use the memo field in a shielded Z-Z transaction to send fully encrypted messages. To send a memo, users must run a transaction and pay a transaction fee, which is less than $0.01.
If you'd like to add, or suggest edits to this wiki page, please head to the ZecHub github repo and submit a pull request.