Because Digital River is incapable of processing a cancellation request correctly? *rimshot*
I'm totally down with the Compendium, find the CB to fit my needs 90% of the time, and loved the Monster Builder for how much custom prep work it saved me (hope the new one is more stable). The magazines are okay, and sometimes have some standout content (Bane and Torog articles, f'rex).
I still buy books because even if 90% of the content is in the Compendium, there are nuggets of fluff and whatnot sitting around that I can find a use for (like all the info on deities and domains in Divine Power and the Primal Spirit roster from Primal Power).