He sent something along the lines of "Thanks for being a dedicated member of this list and for staying with us for these last few months. If you would like to write a quality review for my site and this list in general, I will put your review, along with a link back to your site with the anchor text of your choice, on the homepage of my site."
So I wrote the review, and voila, my site was linked from his. This got me a nice backlink which has generated a good amount of traffic to my site (tens of people per day from that link since the link went up).
So email marketers, take this as you will I thought it was beneficial for him and for me as a subscriber.