Call received @ 1:11 CST today. I called back using caller ID blocking, in case the robocall is meant to build an active phone number database to sell/use on the open market. I got a dial-tone for about 50 seconds and then the receiver self-terminated the connection.
This is the equivalent of getting spam email; a lot of spam email is set up to record an active account by sending information back to a server database once an email account is considered active, e.g., the email is read or the email display image is launched inside the email itself. Spammers make money by selling active accounts/phone numbers, and by commission if their advertisement leads to a sale -- they are typically networked as "partners".
Any vendor that uses shady/unsolicited advertising schemes (phone/email) is untrustworthy.
This number called and when I called back I received a busy signal. Has to be a telemarketer or a person fishing for live numbers to sell to other telemarketers.