Coming soon: test audiences for trailers?

The WSJ reports on new technology which will allow more specific measurement of the effectiveness of various kinds of ads, including movie trailers. One company, IMMI (rhymes with ‘gimmie,’ I assume) uses technology which– I kid you not– uses peoples’ cell phones to sample the noise around them, and then transmits those samples to a database where they are identified so as to discern what song the respondent is listening to, or movie he/she is watching.