Question: Strategies marketing marketplace apps.

Hello all,

There is a lot of prominent marketplaces, such as Slack, Shopify, Microsoft Teams, etc...

I've been lately looking into these marketplaces and probably creating one based on the problems I've narrowed down.

My question is, for people who have developed marketplace apps, what sorts of marketing techniques have you used?

Is it the same as a normal web app, probably a lot of cold emails, PH launch, etc?