They may be collecting phone numbers - waiting for an answer, then hanging up, or waiting for you to call back and then logging your number as valid. For that matter, they may be waiting for you to call back from a different number and logging that number as one that is associated to you. It's like the spam that you receive. Some of them just want to verify your email address, so you open their email, which has some sort of picture in it, and that picture is linked to their website with a serial number, which verifies your email address as being active. Then they take everyone's info and sell it.
They may be collecting phone numbers - waiting for an answer, then hanging up, or waiting for you to call back and then logging your number as valid. For that matter, they may be waiting for you to call back from a different number and logging that number as one that is associated to you. It's like the spam that you receive. Some of them just want to verify your email address, so you open their email, which has some sort of picture in it, and that picture is linked to their website with a serial number, which verifies your email address as being active. Then they take everyone's info and sell it.
I keep getting this number on my cell phone. I have chosen not to even answer it. Not sure how long they or the machine will keep doing it but wished I could add it as a block on my cell phone.