subs, /, or www.

[ASchmitt]

Ok here's the question:

Imagine that you would have a general content site, no main 'subject of information'... the platform contains content about e.g. 5 main topics (in the beginning): marketing, widgets, culture, guns and twins.

Each contentcategorie is seperated from each other and has no relation to each other, besides the fact that they are on the same platform, under the same url.

The goal is to optimise/promote, SEO-wise, each categorie as a seperate site.
So e.g.
http://www.example.com/marketing
or
[marketing.example.com...]

The main site http://www.example.com doesn't have any content on it self.

Can this be done, what will be the effects on the SERPS and can be predicted how for example Google will cope with this and most important: will each categorie be seen as a seperated site?

Regards,
Alexander

[idolw]

both are good.
some use subs for different language versions, i.e. en.example.com, es.example.com

some use subs for geographical locations, i.e. usa.example.com/widgets, uk.example.com/widgets

some use directories for the same, i.e. example.com/en/usa/widgets

i like subs, some don't.
don't treat them as a trick that will make you #1 though.
just look at MSN. it is full of: keyword-keyword.example.com results. thus, no one uses it.