Several ISPs, such as AOL, Earthlink, Excite, Hotmail, Outblaze and Yahoo have announced or started testing feedback loops in the new Abuse Reporting Format (ARF). Why is it good for us email marketers?

For those who don’t know what it is, a feedback loop is a system by which the ISP provides the sender a copy of a message that a subscriber has reported as spam - usually by hitting a “report spam” button.

Why is it important? Because this information is deliverability gold. The number one reason that commercial emailers run into delivery problems is that their complaint rates are too high. With this data, when analyzed properly, allow you to figure out where the complaints come from inside of your email program.

What is the cost to acquire such data? Nothing. It’s free.

Source: Return Path.