Consider supplementing your keyword PPC campaign with listings on Product and Service Pay Per Click engines.

Product Pay Per Click engines enable advertisers to provide "feeds" of their product databases. When web users search for a specific product, the engine returns a list of links to advertisers of that particular product. The engines rank these companies based on who pays what, but also let users sort the list by product price. Leading Product PPC engines (also called Product Comparison Engines or Price Comparison Engines) include BizRate, NexTag, Pricewatch, and Google's Froogle. Similarly, Service PPC engines rank advertisers' service databases, and include NexTag and TripAdvisor. If you have deals on your products services, or regularly have lower prices, these other PPC engines can help you drive more visitors who will purchase your product to your site.