A new search marketing tool will allow small business owners to manage paid search campaigns across Google AdWords, Yahoo! Search Marketing, Microsoft adCenter and Facebook ads from the same dashboard. The new SearchManager is powered by Clickable and offered through the American Express Small Business OPEN Forum.

American Express is offering a 30-day free trial for customers interested in SearchManager. The company estimates that nearly three-quarters of today’s entrepreneurs are not spending money on search-engine marketing, despite the fact that Google alone generated more than $50 billion for U.S. businesses in 2009.