I own 2 Reddit communities with a total of 10000 members. How can I make (more) money from them?

[siclaro]

Both subreddits have same topic: Deals, Savings for products and services. First subreddit has 6K member while other subreddit has 4K member. I am earning about 25 to 50 Dollar per month from it. I don't know how to scale it. Has somebody an idea?

 

[Graybeard]

First of all, you shouldn't use the word own in relation to any social media, because you don't own it.
They just let you use it.
You create product, the membership of the social media, to possibly sell ads in your subreddit.

I'm only pointing this out because one has to be careful about how much effort, and specifically advertising money, into something you don't own that could be deleted or taken from you at will.

One possibility: You might invest $100 and buy some sort of network advertising that's catchy ad and link the network advertising to your subreddit.
If your subreddit is appealing to any persons coming in through the ad, they may join.
No guarantee this will work, but if it does, then you have a way to scale it.
If it doesn't, you've lost $100.