There are some stamps (and dies) that you use for a while, but then they get put to the back of the cupboard (or sold on). There are others, though, that you know that you will never part with and will use and use and use. These are in the second category.
Every year Stampin' Up! retire some products to make way for new items, and it's always a bit nerve-wracking - will your favourites be in the catalogue next year? There's nothing stopping you from continuing to use them, of course - but as a demo you can't really continue to showcase them (because it's not fair to tease your customers by showing them things they can't buy).
We don't know yet if these stamps and dies will be available next season. I hope so. But even if they do retire - I'm telling you now, I won't be selling mine on, I love them too much.
Here's a cute little mini card I made with them -