The card is sent because anyone can buy Memory Maker, not just those people who are staying at a Disney resort or have bought a Magic Band. So people staying off-site without Bands need a way to link to their pics.
Now here's the slight bit of terminology that people get confused on...
PhotoPass is the system that takes photos and allows you to buy them. These are the pics from in-park photographers, on-ride photos, etc. Everyone in the park can use PhotoPass, link photos to their Bands (or get a card from the photographer), and then individually buy the photos. (On our trip in November we could look at our pics online and had the option to buy any pics we wanted on a per-photo basis)
No matter what, all photos taken in the parks expire 45 days from the date they were taken.
MemoryMaker is a photo package that allows you to download ALL photos you have in PhotoPass for a single price. You can download any photos that you had taken, as well as those that you can see because you're linked to Friends and Family and *they* had photos linked to their Bands. (For example, on a recent trip, one friend stayed in the park while my bf and I went to Artist Point for dinner, and the pics of him on Space Mountain and Buzz were visible to me)
MemoryMaker has a 30-day window that starts when you *download* your first photo. Up until then, you can view all you want. And since the 30-days is independent of the 45-day counters on each of your photos, it's possible that photos could expire during your MM 30 days, or not until after it, depending on when you made your first download.
-Rob
