How do you come up with the right campaign metric for measuring success? "Does it impact your relationship with long term customers?" asked Marcus Tewksbury, Global Vice President of Product Strategy at Experian Marketing Services. If not, then forget it, Tewksbury told OMMA DDB attendees on Thursday. Tewksbury also addressed how data should be valuedmore broadly. "Data is based on perceived value," he said -- a somewhat less scientific, quantifiable explanation than we were expecting. Another problem with differentiating good data from bad -- at least for those in attendance at OMM DDB -- is that the more valuable one's data is, the less they want to tell anyone about it, admitted Richard Frankel, president of ad tech startup Rocket Fuel.