So, the purchase of a competing college/university (Rasmussen University) was not enough, they had to buy another school... I'm not sure why as this "graduate school" doesn't offer any degrees, they're more classes/courses and not credit bearing either. I guess they just wanted the school name and domain! Link: American Public Education completes Graduate School USA acquisition | Higher Ed Dive
Graduate School USA existed for decades as a nonappropriated fund instrumentality of the US Department of Agriculture before being spun off into an independent nonprofit. Due to that legacy it still has some currency and likely expertise/contacts/contracts as a provider of training for civilian federal government employees. As such, there's likely some stuff worth buying there for American Public Education if they also want to work in the US government employee training space.