Domains and Sub-Domains

[Brand Digital]

I'm working with a client (Coupa Software | Purchasing Simplified | eProcurement and More) to update their site and content structure to be more search engine friendly. We've identified quite a few areas for improvement, but am having an issue with figuring out why my spider tools aren't connecting Coupa Software | Purchasing Simplified | eProcurement and More with trac.coupa.com (their wiki), forums.coupa.com and blog.coupa.com. All three sub-domains are indexed by google, and the links to those are in the top nav (drop downs, not ideal) but aren't adding to the Coupa Software | Purchasing Simplified | eProcurement and More domain strength (other than to point back to the prime domain from the sub-domain).

Thoughts? Comments?

Thank You.

[hostBrain]

Sub domains have their own dns A record and are looked upon as their own domain.
If you want these sections to inflate the strength of the main domain, then change them to sub folders.