The government scout claim implying it was a legitimate service may an issue. However, a few years ago, community groups were going around my suburb offering this innovative door to door service of painting on numbers on the kerb as a fundraising method for a legitimate good cause. It served a purpose for ambulances,police and visitors being able to locate your home particularly at night.
I have also got metal house numbers free from the Brisbane City Council Ward office and pop riveted these on to the side of my two wheelie bins. This also helps when the bins are put out the night before so they can be collected the next morning. It is also handy to identify which is your bin/s when in a complex where multiple bins are put out together.