What is a good conversion rate for Reddit posts? (Reddit post to email signup) Also, general tips or principles for creating high converting Reddit posts?

It differs from one subreddit to another, all of them have drastically different audiences and rules, It is hard to have general posts that will work everywhere. So the best way to find out is to research the sub-reddits that you want to target and see what kind of posts work on that sub-reddit. After that try to create a post that fits that specific sub-reddit.

Hi, Can you please specify what you mean by conversion rates? In all the reddit groups I posted, the admin blocked my post as promotional 😞

@Anju Aggarwal I have a Reddit post that tells people to go to a TypeForm, which asks for their email. I'm comparing the number of upvotes vs the number of email sign-ups. Before posting on a subreddit look at the most popular posts and see if they allow promotional material. If you're not sure reach out the mods directly.

If anyone is doing Reddit marketing and wants to understand now subreddits are related, I download all 300GB+ of comments from Reddit per month and run some nerd magic on it to understand how people in one subreddit belong in another, so I can give you lookalike audiences for Reddit. Here's an example for r/iPhone