Assessing the performance of an online travel brand in the multi-device world is the greatest obstacle to good attribution, according to Jonathan Isernhagen, director marketing analysis at Travelocity. Before you even think about modeling, you need to de-duplicate your records so that 12K shoppers that visit your site via three different devices look more like 12K than 36K shoppers. This is accomplished in two ways: 1) By marshalling your own internal e-mail and checkout point of purchase data: ‘This desktop cookie and this smart phone cookie both correspond to this user ID’, and ‘the messages addressed to this e-mail address were opened on this tablet and this mobile device….’ 2) There are third parties who have their pixels across dozens of sites and are working to build profiles, and by virtue of their networks they have better odds of figuring out which 20 cookies roll back to one person. They are more immune to the effects of rampant cookie clearing than those of us with individual sites. Get the full story at EyeForTravel