- Greetz.nl is an e-card company with over 3 million cards sold in 2010 and over 500,000 customers ranging from ages 8 to 80. Brand awareness is 60%. - The company wants to change customer behavior from procrastinating to more easily sending e-cards. - In 2010, Greetz.nl ran a multi-channel marketing Christmas campaign including display ads. The key question is what contribution the display campaign made to overall results. - Measuring the effectiveness of individual channels in a multi-channel campaign is challenging due to limitations in attributing conversions and estimating lifetime customer value.