Google is introducing changes to AdWords API Beta program. The changes will be in effect on October 1, 2006. Web masters using the service will be charged $0.25Â (or local currency equivalent)Â per thousand quota units consumed. See the detailed rate sheet here.
While this can add up to considerable amount of money for some advertisers utilizing the AdWords API, this change was coming. Alexa together with Amazon have been charging web-masters and affiliates for similar services $0.15 per thousand quota units.