User blog comment:Rappy 4187/Technical Update: February 1, 2017/@comment-13055710-20170209003544/@comment-126761-20170209151619

The footer is one of the least 'invasive' locations for this kind of content, and it may appeal to people who have finished reading an article and continue scrolling down. Whether or not it works is a good question (and hard to know without testing it out) - we'll be keeping an eye on the stats to help us make decisions about it, and the future of the right rail module.