okay, so I have site mydomain.com < primary site. I have directory links.mydomain.com < directory page I require reciprocal linking, and users will be required to link to primary domain -> mydomain.com so the scheme is: links.mydomain.com ->> user website ->> mydomain.com does this make sense? will google like this? is this black seo shit? is this a good idea?
Matt Cutts recently discussed at PubCon that subdomains will be treated as directories of the root domain, starting with the next Google update (soon). So this would mean you scheme would be treated as an internal link structure instead of an external link back.
Matt full of crap ... heheheh ..well I would not agree.. he has helped more than he has hurt.. and look to make it simple the process's seems right but it is really about long term to see if it worked or not.
for me that is a good idea by if they have the same domain name and the other is a sub directory i dont think that it is a black hat.
If you review the webmasters guide lines you see this displayed... This includes a direct link to the phrase "participate in link schemes" that is listed below. http://www.google.com/support/webmasters/bin/answer.py?answer=66356 I would assume with what your suggesting your trying to "fool" Google in believing the backlink is a one-way, when in reality they are participating in a "link exchange". With it being the same domain name this is apparently obvious. I wouldn't suggest this technique, it is in-directly on your part a way to maniplute search results. Read this for more information by SEO Book: http://www.seobook.com/archives/000467.shtml
I see, in case if I just do normal directory on subdomain, will it have any effect on seo? since subdomain is a seperate site, incoming links won't count for main domain right? and outbound links neither??
Technically yes, but most likely Google has safe guards to prevent PR\SERP abuse from this and may trigger a penalty in the future, this is my opinion but I'd put my money on it.
Cute Idea... But it has been done, detected and Google will not like it. But from the link maintenance stand point, think of this concept applied over ~1,000 links. The maintenance costs will break you.
One rule of thumb to go by is dont try to trick the search engines... Put the time into methods that truly work. You will be much better off in the long run!