I keep seeing people ask this one, and the blunt truth is you can't get a proper, legal PDF download of 'The American Roommate Experiment' unless you buy the ebook. I tried hunting for a free PDF version earlier this year out of curiosity, and most sites that pop up are either scams plastered with invasive ads or have broken links that lead to malware. It's frustrating because you just want to read the book, but ending up with a virus isn't worth the hassle. The publisher and author really have digital rights locked down tight.
Honestly, your safest and easiest route is to purchase the ebook through a major retailer like Amazon Kindle, Apple Books, or Kobo. You'll get a clean file that works on any device with their app, and it supports the author. I bought it on Kindle when it came out—no regrets, and it syncs across my phone and tablet. If you're dead-set on a PDF format specifically, some online retailers might offer that as a download option after purchase, but it's less common now. You could also check if your local library offers it as a digital loan through OverDrive or Libby; you 'borrow' the file for a set period instead of downloading a permanent copy.
I get the appeal of wanting a PDF to maybe print or keep offline without DRM, but for a popular new release like this, free downloads usually mean piracy. The book is still relatively recent and part of a big series, so those sites get taken down fast anyway. Just saving you a bunch of wasted time clicking through sketchy pop-ups.