Next you should keep track of how many people made a purchase after clicking on your ad. Here's a good way to compute this statistic. Take the number of dollars you made off of purchases and divide by the number of advertisements that were viewed.

Another good statistic is to compute your ROI. ROI stands for return on investment. Simply subtract your advertising cost from how much in sales you made on an advertising campaign. It's a good way to weed out your poorer advertisements and also poor places to place your advertisements. There's an excellent online product you can use to track your ads called ROIBot. It allows you to place a snippet of code in your ad links to track all of your advertisment and how many click-thrus they receive. This will assist you in computing your ROI on all of your ads no matter where you place them on the internet. By keeping good records you can come up with good ads and good places to advertise and save yourself a ton of advertising dollars in the process.