Abstract: The key tag mailer comprises a postcard with multiple detachable key tags deposed therein. At least some of the key tags are associated with different advertisers and some have different web address deposed thereon. In some embodiments, some of the key tags have advertising information deposed thereon, such as an advertiser name or logo. A website pointed to by the web address returns additional advertising information in response to queries using the web address. In some embodiments, the web address is encoded in a quick response (QR) code deposed on the key tag. A consumer receives key tag, scans it with a consumer device such a mobile phone, sending a query.