How Important is Passive Advertising?

How important is passive advertising for what you are doing? Either for yourself (you don't care if others see your branding) OR for others?

When I say passive advertising I mean things like the following:

• Car decals
• Banner's on your wall in zoom meetings
• Swag you can send followers (i.e. stickers, branded items, etc)

I have a relative in this business and he is a 'one man' shop so I was thinking through potential customers.