I have been doing some Data Science consulting on the side and last year we did some analytics work for a government lottery and that contract came to us because one of my partner's girlfriend had a relationship with the team who needed the work done. Otherwise you would never hear about any of this stuff that is constantly flying around in the airwaves.
The problem with this advice is that it's not any advice. Saying business is about nepotism is unattractive and doesn't really help you, other then to say, either you are social and good at forming relationships or find a partner that is. And moreover, you can't sell this advice in a coaching class.
If you aren't a social butterfly the only way is to build those relationships over a long period of time and create trust.