Unsubscribe links are far and away the most popular form of email management link used by online retailers - with 100% of 100 major online retailers surveyed using the tool, according to a new report by Responsys.

They are also the only legally required link (due to the CAN-SPAM Act governing commercial email). Another 37% include a link to change/manage preferences, while 22% offer a change of email address link. Eighteen percent include a subscribe link.

Because permission email recipients often unsubscribe due to lack of relevance, high frequency and the desire to subscribe from a different email address, Responsys advises online retailers to include multiple email management links in an effort to reduce unsubscribe requests, writes RetailerDaily.

The report also found that 94% of online retailers use a single text-formatted unsubscribe link in their promotional emails.

The "Responsys Email Unsubscribe Benchmark Study" also reveals that another 3% use multiple text links. This means that a combined 97% of online retailers rely on text-only unsubscribe links. And out of the combined 3% of online retailers employing image-based unsubscribe buttons, two-thirds also use a text link. Responsys analysis indicates that retailers are relying on text for their unsubscribe links in response to approximately half of email users blocking images.