Hi, we're from the Ambulance, and we'd like to walk thru your factory/shop/warehouse and familiarize ourselves with the property so we can respond faster if and when you need us.
A hunk of restaurant grade choreboy sponge removed the other company's sticker quick, and the wet sponge was sufficient to wet the slip decal onto the phone.
That generally got you in so you could sticker every phone in the place.
Of course we also had the advantage of complementary fire extinguisher inspection and there was no additional charge for tossing your used and partly discharged extinguisher in the car to take in for recharge.
There were weeks I made more money on extinguishers and decals than I did on runs. I got a buck for every run to a place I stickered and logged.
The Good Old Days!