Abstract: A machine may be configured to generate metrics or billing reports for online advertising. For example, the machine accesses, in real time, an event cost value associated with an event of consumption of an online ad displayed on behalf of an advertiser associated with an account identifier. The machine accesses, in real time, a remaining budget value associated with the account identifier. The machine determines, in real time, that the event cost value exceeds the remaining budget value. The machine generates, in real time, an adjusted event cost value to correspond to the remaining budget value based on the determining that the event cost value exceeds the remaining budget value. The machine generates, in real time, a real-time billing report including the adjusted event cost value.