The biggest significance of the 360 in a domain is this: it shows that there is a virtual tour or some rotational object photography on the site. It is a strong keyword for virtual tours/virtual reality displays. Growing bigger even in the last few years. I think it will soon be a standard way of displaying products and places on the internet.
Here are some real uses on the Internet right now: it is used for displaying cars inside and out, using the mouse to see it from every angle, inside and out. Check out the websites of Audi, Mazda, Suzuki, Honda, Lexus, even Harley Davidson.
Another wide use of the "360" is for real estate. You can go into a house and see a panorama of a room, go from room to room, zoom in and zoom out. Saves the realtor a lot of time because they can show their houses to anyone in the world on the web.
A few sites have panoramas (some even spherical where you can look up and down) of scenic and tourist spots around the world. Macchu Picchu, Egyptian pyramids, just about anywhere you can think of. Check it out on a site called VRMag.org. One of the best "panographers" is Greg Downing. Go to his site. This is pretty cool stuff. About the most interactive, immersive way to show anything on the internet.
I know a lot about this stuff, so take my word for it. 360 is big.
