Which distribution channel should I focus on first for a B2B SaaS startup?

I’m a big admirer of Paul Graham and a strong believer in doing things that don't scale for early traction. And I’m trying to acquire my first 100 users for our B2B SaaS startup Curatora.io.

I’ve prepared a great collection of Facebook Groups, LinkedIn Groups, SaaS directories, and Subreddits.

Our audiences are mainly social media agencies and individual social media managers. My question is which distribution channels should I focus on first? What is the best channel to reach the right audience?

I'm Mohammed Imtiyaz, co-founder of Curatora.io. I would like to give you a quick intro about us:

A few years ago we set off to create a human-curated reading list for entrepreneurs. This led us down the rabbit hole of information overload and the thoughtful way to deal with it.

Over the years we built internal tools, processes, and systems to make our job easy in curating 100s of content pieces from 1000s of sources on a daily basis.

We have now packed all our learning, experience, and code into a powerful application and made it available for others to use and benefit from.

We started it as a curation tool, but it also allows scheduling and publishing content to social media platforms.

Content curation is something more sought after these days. And our primary focus is on saving time while curating.