Googe Sitemaps and Sites In a Subfolder

Are subdirectories of the main site acceptable?

[hyperkik]

Google has announced new Sitemaps features, including making query statistics available for sites located in a subfolder (e.g., http://www.example.com/mysite/).

This could provide a lot of information to a large website if it were to set up sitemaps for content contained in subfolders, particularly given that you can have up to 500 sitemaps in an account. But the content of the subfolders would not technically be "sites located in a subfolder" which raises a question of whether this might be construed as abusing the service.

Also, assuming that this is an acceptable practice, would there likely be any detrimental effect in how Google perceives a site with multiple sitemaps?

[Quadrille]

Multiple sitemaps are fine for large sites that need them, but Google is very specific about how they should be set up. To get any benefit, it's quite important to follow their advice on this.