Sorry for not responding to this sooner! I actually don’t personally keep many of the cards that I find that are used, and the vast majority are indeed used. I do, however, love finding the unused ones so that I can use them in the future. Before reselling the used cards I find, I really just enjoy seeing the cool illustrations. 

Many cards do have personal inscriptions (which, yes, is sad)… The resale value really depends on the time period of the card and what’s on it. Some of the lots of used cards that I’ve sold that have gone for the most money are “cute” animals from the ‘50s and '60s.

The used cards that I typically keep are unique or mechanical. Adam and I both love mechanical cards. Here’s a great example: 

When opening this card, the woman does her morning stretch… when you close it, the arms tuck back inside. I can’t tell you how many cards I have that are similarly mechanical, fold out, or have other cool embellishments. I’ll start featuring more on here if people are interested. 

As you can see, this card is indeed used–signed “Love & Kisses, Goldie” (I know it doesn’t look like “Goldie”–I only know that because I have lots of Goldie’s cards!) 

-Sarah