Indie Watch - newsletter for indie iOS apps, how to improve conversion?

So, I wanted to try my hand at a newsletter. I "launched" mine a few days ago:

It's an exclusive weekly newsletter showcasing the best indie iOS apps from developers worldwide.

I figured that I'd be able to leverage my YouTube audience, Twitter, and mailing lists from my paid content to provide both the initial user base and some recommendations for indie iOS apps to consider, but the conversion is poor.

I can sort of understand why - it's the chicken and the egg problem. People will only sign up when I can demonstrate the newsletter is valuable and I can only prove the newsletter is valuable once I find good indie iOS apps to cover from the community. I'm searching for apps now, but any other suggestions on how to build that initial user base for the newsletter?