Shopping search engine Become.com will credit 50 percent of advertisers' CPC adspend during August, ClickZ reports (via MediaBuyerPlanner). Credit can be taken in cash or used for future campaigns. Cost-per-click rates for the site range from $.10 to $.40, depending on the category. Ad units are made up of individual product listings based on a data feed provided by each merchant, with paid product listings on the right-hand side of the page in each search. The 50-percent-off promotion seeks to introduce advertisers to the site while it's still in beta.