Obviously low traffic (~30 uniques/day) but very good return per visitor.
The site is a directory type service for a business niche. People who come to the site are specifically looking for that business type so they respond very well to ads for those businesses.
It is page ranked second for the business category as search term - I believe it would double the numbers if it was ranked first. Of course it would still be low traffic, so small change, but it pays for the server. Repeat for a few more niches => profit!
It won't scale. I have similar sites in my 'breakdown', but as soon as any of them get significant traffic it drops right back down to < $0.25 CPM.
I think the reason is simple, as soon as you get in to a very targeted niche there are very few advertisers that match that niche. By the time you've exposed all of them a couple of times the click rate & ECPM drop right back to average.
The site is a directory type service for a business niche. People who come to the site are specifically looking for that business type so they respond very well to ads for those businesses.
It is page ranked second for the business category as search term - I believe it would double the numbers if it was ranked first. Of course it would still be low traffic, so small change, but it pays for the server. Repeat for a few more niches => profit!