Setting up your category structure is very important.

When you build assets such as Text, Email and Mailers, you'll want to add them to the appropriate category. This will help you locate them at a future date.

This is important for when you build campaigns. When building a campaign, we ask you to define the "Categories" you'd like to expose when building that campaign, instead of showing you every text, email and mail template.

You can assign any asset to multiple categories.

We don't currently have sub-categories so you'll have to work around it.
Let me give you an example.

If I'm building assets that are specific to "homes that I Just Listed" then I'll create a "Just Listed" category. If I'm making a postcard, I'll will also add it to a "Postcard" category.
Now, in the future I can find my postcard in both the "Just Listed" and the "Postcard" category.