So I just set my account up today. My (parked domain) AdSense for Domains has made money. But my other website which is actice and has had multiple page impressions and ad clicks has made no money what so ever. Why is this? How can I fix it?
You should promote it better and you should change the position of the adsense ads. Maybe that will work.
I would try creating a URL Channel for your site by going on your adsense admin page -> adsense setup -> channels -> URL Channels -> + Add new URL channel
Yeah, maybe you need to work on ad positioning. You also need to make sure your website is drawing in people with buying keywords, and not browsing keywords.
promote you sites, update it daily, bookmark the post, and also submit your site in directories, this will help you to get more visitors, more visitors mean more clicks mean more earning!!!
Depends on your niche. Some niches just don't have many advertisers. Therefor, if adsense doesn't have an advertiser they will serve up PSA ads that don't pay you anything. Or, it could also have something to do with your ad position too. It's hard to answer not knowing more about you site. Good Luck!