I have a web site who's home page is at http://domain.com when a new user first hits the web site I'm creating a unique id of 5 chars for them (for example 'abcde' and redirecting them to http://domain.com/abcde so they can later bookmark and return to their workspace. My question is what's the best approach for SEO purposes, I need the main url domain.com to be indexed but google will also get the redirect and will not index the main page. I know about canonical urls, but this applies only when the domain.com url does not redirect also should I use 301 or 302 code in the redirect ?