i added my site name to the main page good idea thank you
and "people will return when new or interesting content shows up?"
- how will they know? they never activated their profile by confirming it, and all that jazz. so there is no mechanism to notify them. and if they get dozens of emails about so and so posted a post in their email they will unsubscribe get pissed and forget the whole thing ever happened or worse call you a spammer.
people dont really give a &^^&&^^& about this stuff unless they are diehard into social internet, its not a priority at all for them. so they wont remember unless they are engaged.
the best way i know of so far is to get them interested from the get go, and to make an emotional commitment to coming back later. :) on their own.