I've posted Brisk Voyage to a few travel subreddits over the past few weeks, and got around 2,000 new subscribers, bringing the total to 2,500! I think there is a more niche audience for this type of "travel hacking" email list, so it fits well in subreddits such as /r/shoestring and /r/travelhacks.
After posting to a few subreddits and getting positive feedback, I decided it's time to launch to Product Hunt. Even though Product Hunt has a more general audience, I think it could be useful to some people there. Not many upvotes so far, but it's worth a shot, I figure.
I'm thinking that it's smarter to post to Product Hunt before adding some sort of premium/revenue generating feature? Because then the product is more simple and people can more easily understand it. Later, I can try to convert those users to the paid features.
Here's the Product Hunt posting! https://www.producthunt.com/posts/brisk-voyage