I think a general pattern is people subscribe to subreddits and just let reddit do it's thing to populate their front page, never actually visiting the specific subreddit. I do this myself for a lot of subreddits I subscribe to.
I wonder if reddit has any plans to modify the ad display logic to display ads on the front page that are targeted to specific subreddits if the user is subscribed to the same subreddit. I think that'd be interesting.