Honestly, with 4k users and 60k page views, you're still in the "what works?" phase - and most people barely break even at that stage. a lot of apps at this level end up pulling from a few plays:
• Tossing in standard ad networks (AdSense and the like)
• Routing traffic toward other social, dating, or cam platforms on revshare
• Selling some kind of premium feature inside the app - boosts, visibility, private filters, whatever.
When it comes to affiliate stuff, most networks won't even look at you until you've got cleaner targeting or bigger numbers. You might have better luck going niche rather than chasing big networks. Find one or two products or services that genuinely match what your users already want, then pitch those to smaller or direct affiliate programmes.
But yeah, at that size a lot of folks are basically testing what sticks rather than actually making money. It's normal - just keep experimenting.