Using newsletter subscribers as focus groups

Content.ly, the firm specialized in creating branded content, did an interesting survey with its readers, and they shared all the methodology here.

The best idea: they've used Mailchimp "star system" (which ranks the subscriber in terms of newsletters opened and links clicked) to split the answers between the users that are engaged (4 and 5 stars) and the "control group." When doing surveys, it's always hard to create a control group and do focused testing, so this is a nice, fast, solution.

Another interesting bit is that they've used the  "Net Promoter Score", a common way among marketers to find out who is your "brand advocate." I didn't find their rate particularly high, but that question (and answer) should be attached to every media kit out there, I think.