Must the Memory Maker One Day be purchased at the park or can you purchase it online when ordering a 1 day ticket?
It can only be purchased as an add-on to a ticket, and I believe you may only add it at Guest Services. This says Magic Kingdom.
http://wdwnews.com/wp-content/uploads/sites/3/pdf/disneys-photopass-service-makes-viewing-sharing-and-ordering-walt-disney-world-vacation-photos-easier-than-ever.pdf?t=1448714117
Shucks! I called to ask more about it and the CM said that it is no longer available. I was hoping they extended the offer.