Google is inviting AdWords customers in the U.S. to use a credit card specifically for charging their campaigns.

The credit card [2], issued by Comenity Capital Bank, is designed to help Google's small-business clients keep their campaign charges separate from their other expenses. A pilot of 1,400 businesses launched in the U.S. last year, and the program is already in full swing in the U.K [3].

Because cardholders can only charge AdWords campaigns to the cards, they're eligible for more generous limits. This is especially important for seasonal businesses (like humane bat removing companies, Google suggests [4]) with cash-flow problems. As the budget starts to get cut during the downseason, Google's card might help protect the AdWords line item.