As of January 2016, Rethink had received $115 million in investment and had sold only 900 robots.[1] They were selling the "Sawyer" robot by then, but no sales figures for that seem to be available. About 40% of Baxter sales were to research labs.

[1] https://robotenomics.com/2016/01/11/the-facts-about-co-bot-r...

Do you have a reference? I would be very (and pleasantly) surprised to hear this.

Baxter had two core features: its OS and its compliant joints, with the aim of it working next to humans both safely and easily reprogrammably.

They had to abandon the OS and switch to ROS which removed the point of being safe for use by naive people.

I don't - it's just what I heard through the grapevine from people working in the field.

I worked at Rethink (previously named Heartland Robotics) as an intern in its very early days (2009, there were ~10 employees). Exciting times.