To tell you the truth i was glad it was finally running out as i felt bad they were funding people/content providers somewhere in the world for fraud.
So in the interest of sharing i thought i'd share the results in case anyone is interested and open it up to discussion.
Spent $20 - had 883,911 text banners displayed in 15 Days.
Over the 15 days, 382 people clicked on the banners or approximately 1 in every 2,314 displays (in green).
Each banner cost me 2 thousands of a cent to display, or 0.02 cpm (in red).
Each click cost me 5 cents (in blue).
Now interestingly we charge $1 cpm to display ads on http://www.livebaseballchat.com/ - so we will display 1,000 banner ads for $1.
1000 ads = $1.00
100 ads = $0.10
10 ads = $0.01
1 ads = $0.001
So if it cost me 5c to get someone to click to my site i need them to view 50 ads before i make a profit. As we rotate our ad every 60 seconds I need them to stay on the site approx 50 minutes (or for them to come back over a period of days for a total of 50 minutes before i start making money).