Yes,i think is true. You know why? Cause when you have contact, you can know who have more than talent you. And, you can ask they for help you while have problem

so that they can vouch for you if need be.

Definitely! Having contact it is a key value to reach different goals. In the first place it could help you to promote your talent. On second place it is very important to know who has specific skills that may come in handy on any difficult situation.