I received a call to my voicemail and they hung up. I assume this is one of those services that calls to see if it is a valid phone number and a time when you will answer the phone. They can then sell the information to telemarketers. Just guessing....
The same here, For the past week around 9-10 am, they just call and will not leave a message. I am sure the time will change as I believe this is one of the several outfits that just calls to see if anyone is at home and at what time so they can sell them to telemarketers. I never answer because its just a waste of my time.