Are SPDIF jacks special?

I have these headphones called Astro A30, and they are SPDIF compatible. When I use them on my xbox or PC with compatible jack, they sound amazing, espeically in gaming. Yet, whenever I google SPDIF, there doesn't seem to be much hype in them. Also, my headphones company didn't use SPDIF as one of their selling points. Why are such seemingly awesome features downplayed?