Has called about every single day and never leaves a message.  Have no idea who or what they want, but they are pretty persistent.  If it was important enough to call every single day then it's important enough to leave a message about who they are and what they want.  I've blocked them as I'm tired of getting the calls while I'm at work.

Calling me a lot now too. 3x today. Never a message.  back-to-back calls, like a machine did it.

This is SiriusXM.  They've called about every other day (I'm in a 3 month free trial since I just bought my vehicle).  No reason for them to call, much less every other day, and not leave a message.  They always call when I am at work.