> Why bother calling if you are not even going to attempt to scam me.

I think it might be something silly like confirming the number has a person on the other end. For selling to other spammers. Not sure why they can't do both at once though, so maybe I'm off.

They call more people than they have available to answer the phone at the other side. Normally, many phones won't answer. When more phones answer, they just hang on the ones they can't handle.

And, obviously, they can save a bit by always having more phones answer than they can handle. This way their employees don't waste any time waiting for a call, instead it's your time that is wasted, what costs them nothing.

And they can save your number to call back later.

Pretty sure that is the reason. It's the phone equivalent of verifying an email. They ping, you pong, it goes on a list of verified numbers.

It isn't, though. Getting a ringing response is enough to validate a number, and someone who isn't making the effort to check contact lists against do-not-call registries won't be making the effort to track numbers that do not answer, either. In any case, RTNR to such people simply means that there's no-one to answer right now and is no reason to discard a number.

See https://news.ycombinator.com/item?id=16871131 and https://news.ycombinator.com/item?id=16873537 for what's actually happening.

Reminds me of "scam baiting" which is becoming a popular live stream opportunity.

I occasionally watch this guy who calls tech-support scammers or IRS scammers and attempts to waste as much of their time as possible. He will often impersonate an old lady using a voice modulator (or he'll implement other personalities) to make his performance more realistic. It can be quite entertaining.

https://www.twitch.tv/kitboga

They're overbooking their calls. Many people are dialed up simultaneously, but there's not enough people to service everyone at all times. As you answer the call, everyone is busy servicing other people that also answered - your call gets hung up.