We are in a similar boat from the b2b side - we sell a small % of our software in the Amazon and Azure Marketplaces.
Importantly, we don't compete in the Marketplaces for advertising, just work with them for final purchasing, and what our bigger users really like, easier self-hosting POCing. (Infinite trial, even.)
For channels, we instead work with graph databases (Neo4j, Neptune, ...), security/IT log systems (Splunk, ...), AI framework providers (Nvidia, ...), and federal partners so as their communities want to answer graph-y questions about their data easily, they know we do cool GPU graph viz and now graph autoML. Our demo blogposts, talks, notebooks, streamlit apps, etc, are useful tutorials for how to do these. At this point, we are lucky enough to have built a small community as well. Even in the case of Marketplaces, we do collaborate with those companies... But then database teams whom we help create more complete (complementary) offerings.
So the question is who are your communities, which depends on your app.
Btw, if interesting to anyone, we are hiring infra + backend :)
