The story is quite old, before the advent of the internet, which I used to tell my students many years ago. One of those students reminded me of it a few days ago when we met, even though the story was told more than 15 years ago.
To make a long story short, there was a company in America that made patios. Its sales were not satisfactory, but by studying the sales data, it discovered an interesting statistic that would literally save it.
It noticed that several of the sales came from neighbors - something like "show me your neighbor, and I'll tell you who you are." Therefore, it created a very clever marketing strategy, according to which it would approach the neighbors of those who had already closed deals to redesign their backyard. In this case, the neighbors would function as a reference group, as a group that some would want to penetrate.
When someone collaborated with this company, its staff would find out who their neighbors were. Later, they would send them a note expressing regret for the noise that would come from the work taking place at the neighbor's house, while also asking them to show understanding at the same time.
But there was also a follow-up. When the work was completed, a second announcement would inform the neighbors about the completion of the work, thanking them for their patience shown, but also encouraging them to visit the site to see the quality of the work...
Brilliant! A few months later, sales had skyrocketed, mainly coming from neighbors of those who had signed up in the first place...