What’s the Scam?

A security measure on a newsletter subscription webpage requires users to reply to a confirmation email to prevent unauthorized subscriptions. The webpage's owner has recently received numerous responses to these confirmation emails, all containing brief, generic expressions of appreciation for the newsletter's content. These responses are unusually uniform and have been arriving in large numbers since last weekend. The owner is highlighting this phenomenon, suggesting it may be related to some kind of scam. The responses all consist of a single line of praise for the newsletter. They appear to be automated or fake.