Costco marketing email has fake unsubscribe link

I signed up for Costco’s emailed specials a while back and decided today that I didn’t need them anymore. Mousing over the “unsubscribe” link at the bottom of the email didn’t seem to do anything so I decided to look at the message’s HTML to find out why.

It turns out Costco’s unsubscribe link isn’t a link at all, but is just made to look like one. Here is the code:

< p > In the past you provided Costco with your email address=C2=A0 [EMAIL REDACTED]. Occasionally, you will receive brief advertising ann=
ouncements regarding special items and services. If you no longer want to r=
eceive these advertisements, please click < a > < span style=3D"text-decoratio= n:underline;color:#069" >unsubscribe< /span >< /a >.=20

It’s a span, not a link. Here’s how it renders in Thunderbird:

There’s an “update email preferences” choice also in the email but, like the unsubscribe “link,” it isn’t real and doesn’t go anywhere, either.

I think Costco is a great company and I trust them. Still, I’m curious about why Costco felt the need to include fake links in their marketing email.