The SEO user presented question he’s replied:
I am wanted to ask about how Google presently views subdomains — either there’s any difference b/w a site structured as a group of subdomains and one structured as a group of subdirectories.
They’re more or less equivalent, says Matt Cutts. I would essentially go with whichever one is easier for you in terms of configuration, your CMSs, [and] all that sort of stuff.
If you want more information about subdomains vs. subdirectories, you can view the video for a more complete answer.