Which comes first - the subscribers or the content?

I can't really say from experience because I only launched a newsletter after having a fair number of followers on Twitter, but if you haven't read it yet this resource was pretty interesting to me:

"How To Grow Your Audience With Interviews [A Guide]"
https://www.starterstory.com/how-to-interview

I'm leaning in towards content. You need to "at least" have some content direction or samples to grab subscribers attention. I really like how Substack encourage us to do it.

Would love to read your newsletter! Looks like we share a similar vibes, mine is Virtual Mojito. Keen to hear your feedback too haha @jjdinho

I went through this thought process myself, trying to create a new platform for rich html messaging - without using email as the delivery vehicle. How can you get people to sign up and subscribe when there's no content to subscribe to? How do you get people to sign up and create content when there is no one to subscribe to the content?

Ended up deciding that you need content creators first. Then help the creators gain subscribers via the new method. In your case, I think the value from the interviewee perspective is that it's still an opp to get their message out there - or at least to fine-tune their ability to convey the message. So even if you don't have subs, you're both getting better at the process.