Not to distract from your question but are signs and stickers still relevant? Personally I think so but probably not as much as they were back say in the 90's. Yeah I'm old. Back in the 90's typically if you had a sign in your yard you were less likely to get broken into. These days I'm sure it helps as much because lazy people who won't work for a living will go around and check for unlocked doors and just brazenly walk into your house in the middle of the day and grab a couple of items and run out. This was an issue near where I live a couple of years ago.
What I do think the signs and stickers are good for is getting and keeping your name out there. Especially is you do commercial work. Make sure all your panels, recorders and keypads have stickers with your phone number on them. If you do access control then a key chain with the panel keys with your logo and phone number is a good idea as well. In the commercial market lets say you have a system in place for a few years and whoever deals with security leaves. Then unless you have a great relationship with others or your information is not readily available then the customer is likely to just google someone to come fix whatever the problem is. If your name and number is on the keypad, panel, NVR, etc then that customer is more likely to pick up the phone and call you when service is needed.