There are two type of publications in the market. Simple and rich contents. You can identify these types by names and a small chain sign in the corner. The difference between two is that when you import a simple notebook, you just import the notebook whereas for rich notebooks you import notebook, packages, datasets and all dependencies. Here are the examples. It is a simple notebooks:
And this one is a rich notebook:
When you import a simple notebook, it goes to your inventory and from there you can download it to any workspace you'd like:
When you import a rich notebook, it also goes to your inventory, but you can create a workspace with that to have all dependencies. In Create Workspace section, you should choose, from "source file", choose the notebook you've got from marketplace and the rest is similar:
As you can see, notebook, dataset and all packages are included in the workspace created and ready to run.