Hope this helps, but my Brit customers are soldiers serving in garrisons about 30 to 50 miles from where I live. Because of postings and people leaving the army, I canvass twice a year. I drop leaflets telling the tenants that I'll be calling soon to see if they are interested and that we work 6 weekly etc. Then I knock within 48 hrs. While the topic is still fresh in their minds. Works really well for me as long as I knock within that time period. Any later, and it's less than half as good.