Approximately 70% of CBS's revenue is earned through advertising sales which are particularly vulnerable to economic downturns. Furthermore, many of CBS's business segments including television and radio broadcasting are undergoing a secular decline in advertising because of the rise of Internet advertising- as a result, CBS's revenue may decline up to 25% this year. In Q4 2008, CBS's revenue declined by 6% following significant drops in advertising expenditures in its television, radio, and outdoor segments. Additionally, automotive ads typically account for about 30% of CBS's advertising revenue. Therefore, the turmoil in the automotive industry will most likely spill over into CBS's advertising revenue for at least the next year.