I bought these in 2008, and they are still in great condition. They look just as good as the day I got them. The set is comprised of six magnets. They are small, so I don't use them to hold up papers. I use them to decorate my mini-fridge. The letters on the magnets were cut out of a vintage 1960s, McCall's magazine. The glass that goes over the letters looks like those flat-bottomed stones you can get for an aquarium.
When I saw these I definitely wanted them. I am an Etsy geek, and I wanted something to represent my fandom.
I don't have anything negative to say about these. The magnets haven't fallen off the glass marble part. Nor, have they ever gotten cracked. They stay on strongly when I slam the fridge door. The only thing I wish is that they were bigger, but for $3.00? I don't really mind, and at this mini-size, they're very cute. They measure approximately 3/4 of an inch each.
For more information on the seller, see her shop here: link.