Disney has been given a lot of carte blanche in the US to grow and absorb everything in its wake. The above video by Half as Interesting shows how Disney made their Disney dollars a legal currency at an exchange rate of $1 DD to $1 USD.
[…] they are not compatible with coin machines, and must be exchanged for U.S. currency if machines are to be used. In addition, if Disney Dollars are used for purchases and change is given, the change is provided in U.S. currency.
They are often kept as souvenirs or collected by Disney memorabilia fans, but at Disney resorts, they can also be exchanged back to U.S. currency.
Disney stopped distributing and printing the currency on May 14, 2016; however, they will still accept them in the future.via Wikipedia
Money related: The precarious economics of gift cards