After total spending fell over the Thanksgiving shopping weekend, all eyes were on Cyber Monday, as retailers looked to score more sales, especially given the strengthening consumer over the past several months. The most effective form of communication for retailers were emails to consumers, which drove 23.9% of online orders on Cyber Monday. The data comes from marketing and analytics firm Custora, via its index of 100 online retailers and accounts for 100 million shoppers. The firm also said sales on Cyber Monday rose 15.4% year-over-year. TheStreet's Scott Gamm speaks with Corey Pierson, Custora's CEO.