Those mail-in warranty cards usually have one purpose. All those questions they sometimes ask are for gather marketing intelligence. Even a simple name and address is useful to marketing.
Insolvency
I have visited and bought from a small high end shop for the last two years. Just today I went down to the store to buy some accessories. The store was dark and the front door had a sign on it: "Insolvency sale delayed until Monday because of sickness." I was shocked and sad since the store was run by two trully passionate long-time audio hobbyists into vinyl and nice tube gear. It was different, innovative, carried hard-to-get equipment from small, underground manufacturers. Here is my question: over the years when I bought a piece of equipment from the store, they would keep the warranty card with the promise to take care of repairs if the item broke. Now that the shop is gone, I have several pieces of equipment whose warranty I am unsure of. Will the manufacturer repair if I just show a receipt from an out-of-business audio shop? I assume that I will not be getting any of my current orders from this shop (luckily, I did not give them any cash deposits in advance). Have any of you had similar experiences?