Something that you may have observed in almost any field of work is that once momentum starts to pick up, the people that support you or your work will begin to promote you themselves.
However, it’s not that you no longer have to promote yourself.
But what happens is when you build up a network/group of people that believe in what you do they will eventually talk about your work with the people they know and words will spread. Essentially you end up getting free promotion without even asking.
It could be something as simple as when someone asks for a recommendation, your brand/work is what they bring up. However, over time it may go further, to the point where your work is brought up as a conversation starter rather than in response to something.