Every time you meet with a customers, partner or investor end the meeting with the following phrase.
“Can you introduce me to three other people that I should talk to?”
Three is the magic number because if all you ask for is one introduction then that’s all you will get. Asking for four feels like too big a imposition. But when you ask for three they will generally be able to give you one immediately. They’ll have to think for a bit before they come up with a second and then promise to get back to you with a third.
Mostly that third introduction never comes, however that gives you an open invitation to reconnect with them at a later stage to ask for that third introduction that they promised.
No matter how useless a meeting felt always ask for introductions. That each meeting lead to the next opportunity.