• JezC

    Google can and does reimburse spending in excess of 120% of the daily budget. HIstorically it is listed as an “Account Budget Overrun” in billing reports – see this short 2006 blog article describing the issue http://blog.merjis.com/2006/09/14/adwords-budget-overrun/

    It is possible to manipulate an account to deliver a “free excess” of clicks. There are clauses in the Terms of Service apparently intended to allow Google to take action against an advertiser who appears to deliberately exploit that weakness.