If i have a domain sub.mydomain.com having a pagerank of 3, will my main domain get any benifits ? I m thinking about this, cuz i have few domains ununsed and i am thinking of creating subdomains and giving it to people so they can create whatever they want. In turn, it will maybe benifit me more in SEO, getting my site indexed betteR ?
Google treats domain and subdomain as two different website altogether. So think your subdomains as new domain.
It would certainly benefit your site as long as the content is relevant and in addition to the point mentioned by rishirajsingh