Paying for free stuff.
A friend made a post this morning that got me thinking. There are any number of web-/net-based services out there that are the modern-day equivalent of shareware. The services are available in two modes: free and premium (even if not using those words). The service in question in the original post was Spotify, but there are countless others out there.
My question to you is this: Which of these services do you actually pay for, and why? (Are there features behind the paywall that you want, or do you want to pay for a good product which you find useful, or both, or some other reason entirely?)