Problem
People do not like solicitors. Especially as more people become less interested in social interaction because of technology. They don’t like door-to-door salespeople.
Solution
A funny e-commerce company that uses its brand to buy its way into homes. Sell no soliciting signs online. You could have all sorts of types and brands of no-soliciting signs. The reason the business would work is mostly because of the marketing and brand. You could make it silly and interesting.
Example
“Where pest control meets real pest control.” - with a great photo illustrating how your sign keeps salesmen away.