Like example, if you bought a walgreens gc online and got reward from xyz reward program for that, then use walgreens card to buy disney card.
My Walgreens will not allow you to pay for gift cards using a Walgreen's gift card.
I just read the Disney gift card terms and conditions from the link on the Mypoints site. It says it can be used in select locations at the parks. It can be used to pay for DL tickets over the phone and you will soon be able to use it pay for WDW ticket packages.
Does anyone have actual experience using these at WDW?