The pay is low, and they rely 100% on the client to give you a raise. So even if you're a top performer, Concentric is unwilling to go into its own pocket even a little to pay you appropriately.
They also revoked a $50 per month phone stipend two weeks before the holidays. It's not a lot of money, but it's certainly the opposite of saying "thank you" to your employees. The right (and smart) thing would have been to tell people in advance and revoke the stipend in January. To top it off, they sent out a Glassdoor survey a few days after we found out about the phone stipend. I've never worked in HR or employee relations, but even I can see the lack of strategic thinking there.