Each of the search engines that have launched PPC platforms (i.e. Google, Yahoo!, MSN, etc.) have provided an opportunity for attracting sustained, targeted visitors. What's more, those visitors will often be ready to make a purchase decision. If you can position your company in the right space at the right moment, you'll enjoy a healthy boost in traffic. If you can deliver that traffic to a carefully designed sales process, you'll enjoy increased sales and revenue. The challenge is developing the system.