I had two suspicious people come to my door (separate incidents) which resulted in me getting a video doorbell (I'm going to migrate from a cloud one to a closed circuit one).
I've also had two cases of salespeople who didn't understand the phrase "not interested". One escalated to me threatening a trespass call before he left. (This is with No Soliciting signs clearly visible)
If it's 90° on a hot summer day and they are wearing a big bulky jacket, that raises eyebrows.
Are they wearing a uniform? If they are pretending to be part of a company and not wearing a uniform, that is suspicious.
What about the time of day? ADT sales people don't knock on my door at 8pm at night.
How are they acting? Are they waiting calmly? Are they checking their pockets or waistline? Are they glancing around seeing if other people are around?
Are they hiding their face?
Did they ignore a no soliciting sign?
Did they walk by and check out the property before approaching the door?
Did they knock on my neighbors door first? Or did they come straight to my door?
Did they park? Where did they park? Was it a company vehicle?
How many people is it? Are those people dressed in a similar way? Are they all standing together or did one of them wander off?
If you don't answer immediately, how do they act? Do they get annoyed and wander off or do they become insistant? Do they escalate to knocking or shouting?
I guess it depends where you live and what experiences you've had so far. Your 'pre-test' probability I guess. I doubt there is much I would see on a video feed that would stop me finding out for myself who they are.
I've also had two cases of salespeople who didn't understand the phrase "not interested". One escalated to me threatening a trespass call before he left. (This is with No Soliciting signs clearly visible)
I worry my wife would not get the same effect.