I came to JRiver from iTunes in maybe 2008-2009 IIRC? My library needs had vastly outpaced what iTunes could cope with and converting to ALAC was becoming a headache. Furthermore, I found JRiver to be as good as Amarra sonically, while having of course, a lovely UI as well. Not only that, but you guys were WAY ahead of the curve when it came to interacting with JRiver via remote, touch interfaces. The Library Server / Client paradigm was implemented long before anyone else was really doing that in a competent manner and it opened so many doors for me from a flexibility perspective.
Eventually around 2011 or so I became 100% invested in ditching physical media for my extremely extensive film and television library (I was a lucky kid who really liked movies okay? ).
I was occasionally streaming files to a BD player during this time and realized how incredible having every film in my library a click away would be.
I'd had flirtations with the idea of ripping / backing everything up but with probably over 1000 titles, it seemed monumental, especially considering storage at the time. So it progressed, slowly but surely, eventually more physical discs retired in favor of more external hard disks on my shelf.
Then, I got tired of the BD player. It didn't support lossless multichannel bit streamed audio (this is before there were rock solid software decoders for DTS-HD. Thanks Hendrik, pretty sure you solved that with LAV) and I spent a while trying various streaming devices. They didn't impress me so I built a dedicated PC.
What better way to watch my movies than JRiver which I already love, and oh man, there's a way to do chroma scaling with a GPU? I was sold.
I've never really used anything else for critical viewing since. The audio engine is what makes it IMO.
Realizing I could for example, have active crossovers, per channel DSP etc, all in the box, at my source, without buying a Pre-Pro that costs 5-20K (at the time, the only thing really offering that was a Trinnov) was the nail in the coffin. You can't beat that, especially when we're talking about video playback. I haven't looked back.
I used pre-pros for a few years as glorified multichannel DACs before moving over to studio interfaces and now a Topping Dm7.
None of that would have been possible without JRiver.
I recommend JRiver consistently to audio focused clients who are after extremely powerful library management tools. It's pleasing, comfortable, yet, capably utilitarian navigation scheme that's in many respects, mostly limited by your imagination / expression prowess. This makes it a perfect fit for many users, especially older ones for whatever reason.
Furthermore, if someone asks me about critical video playback for their HTPC or theater room? 99% of the time, my answer is JRiver. You guys have absolutely gotten this one right.