Can someone help me understand the use of multiple categories?

I’m going through the videos, but I’m trying to understand the benefit of using more than one or two categories for a given listing.

I understand that a restaurant could be under the Restaurant category, and perhaps the Chinese category, but how would a member use 30 categories? That’s the value for the Example Packages, and I’m trying to figure out how I would sell this feature.

Thanks in advance!