Thanks.. good tips so far. The income has been steady for about 2 years now.. so I'm thinking maybe the best thing to do is just to do some seo, focus on that and increase traffic.. that way I don't have to add more ads either.
If you hate ads, you should just show more of them to non-logged in users.. It can even be an incentive to get them to sign up if you mention it on the site :) Do you know the % of pageviews between logged in users and guests?
