On Cyber Monday, 77% of the top online retailers tracked by the Retail Email Blog sent their subscribers at least one promotional email, setting an all-time record. This was up from 71% in 2009. That increase was preceded by strong growth in email volume on Cyber Sunday, when 56% of retailers sent email, up from 45% in 2009.

Some things only change a little, like deliverability, rendering and spam issues. But the marketing world and email's role in it have begun to shift over the last 12 months, and the repercussions from those changes will be felt as trends for the next 12.