Hi, Are any of you willing to share how your Customer Acquisition Costs (CAC) for mailing lists compares with your CAC for online advertising like PPC campaigns. I'm basically wondering about... 1) E-mail opening rate 2) CTR 3) Conversion Which together culminate in the CAC cost really. So if your PPC CAC is $5 for instance, how does it compare with your mailing list CAC?