There are a number of ways to analyze your stats …
You can compare the number of impressions it takes to get a click, the number of clicks it takes to get a download, the number of downloads it takes to get a depositor, profits divided by total number of players and so on …
A general ratio that a lot of the programs quote is 30:30:10 in percentages. That is to say that 30% of your impressions will generate a click, 30% of those clicks will generate a download and 10% of those downloads will generate an account.
Example: Lets say you give a particular banner 1000 impressions you would expect to get 300 clicks – approximately 90 downloads – and 9 real players using the general rule outlined above.
The better your traffic the higher those percentages will be 
Hope that helps a bit 