The Interactive Advertising Bureau (IAB) has announced proposed guidelines (pdf) for measuring impressions for what the IAB calls "broadband video commercials," which can include any type of in-stream ad, reports ClickZ. The ads can appear in streaming videos, animations, games and music video content. In-banner units aren't included. "The only thing that's unusual about the video guidelines is that we haven't normally dealt with categories that are that small, but given the importance of this to the future, its importance to the members, we decided to work on it now," Greg Stuart, IAB's CEO, is quoted as saying.

The fundamental provision is that an impression be counted only when the actual advertisement begins appearing on the user's screen rather than when a request for the stream or the initiation of the buffer is detected. The guidelines suggest that pre-roll, mid-roll and post-roll ads be tracked and reported separately, but accept that some technology now in use may not allow doing so.

The IAB is accepting public comments via its website for the next 30 days. The final guidelines will be issued May 15.