Getting first customers after publishing what actually worked for you?

I published two transactable SaaS offers earlier this month (Microsoft 365 security and compliance assessment). The technical side went fine, with good
support from the ISV team. Getting the offers in front of customers is where I'm stuck.

So far I've reached Rewards Tier 3 and activated the listing optimisation benefit. I understand customer references are the gate to co-sell readiness,
which feels like a chicken-and-egg problem when you have none yet.

For publishers further along than me: what actually produced your first few customers? Was it private offers to targeted tenants, co-sell once you had
references, the Marketplace Rewards activities, or something outside the marketplace entirely?

I'd rather spend my limited time on what works than keep guessing.