E:D Powerplay: What makes a system profitable?

I'm outside my Power's bubble on the map, and not in anyone else's bubble either, just a free system that is up for expansion.

Even though it has 2 pristine metallic rings, multiple Resource Extraction Sites of every intensity level, and a big population (shown below), it's labeled as a low-profit system on the galactic map. The only thing I can see that might make it less than awesome is that it only has one station, but it is a full-size decent station and located at a planet with a pristine metallic ring. It's awesome.

As a miner, I want this to be a controlled system of my Power, but I don't think anyone will help if it's labeled as low-profit.

• What makes a system profitable?
• Can I make it more profitable somehow?

Yes, I'm conspicuously hiding the name and location. Pirates are everywhere, even SE.