The rates are based on circulation and measured in "Cost Per Thousand" or CPM. You can find most published rates in a directory called Standard Rate & Data or SRDS. Every magazine publisher also lists the rates by size, placement and color/black & white in their Media Kit which you can get from their media sales office. Most major publications are also audited (ABC is a major audit bureau) by an outside firm to insure that the circulation and readership claims are legit. Look at the magazine/newspaper's masthead for contact information. The frequency of the ad (every other month or each month....) will affect the rate. The more ads you sign up to run, the better the discount.