This question already has an answer here:
If User A is able to store the URL of his website on a very popular highly ranked website by creating his own subdomain on that website, is this at all beneficial?
This may sound like a stupid question but I thought that no matter the popularity/quality of the website which is hosting your link, in reality it is the individual page that hold the rank and so your new subdomain means nothing as it is not yet cached by search engines, let alone is it even ranked!
Am I right here, or is there indeed a hopeful transferal of at least some authority to subdomains of a popular domain? Lastly would you say it is the job of the website admin to submit his new content for inclusion, or is that our job?