If you ever wanted a classic example of why Free doesn't equate to Open Source or Free Software (Free as in Liberty), here you go: "A fork in the road (An important announcement about I want Sandy)". Note the comments below on how people invested time and effort into a service, yet that service is now disappearing because of an acquisition. *POOF*! Sorry! Thanks for playing! We've seen this pattern time and time again where someone's business needs don't match your personal or professional needs, and suddenly you're left without recourse. I used I Want Sandy for a while as an auxiliary calendar (I use Google Calendar for my primary calendar. No, the irony is not lost on me) and it was quite good. I could see why people wold use it. It didn't do everything I wanted, and I still found Google Calendar and Tracks to be more of what I needed, but it was a unique and useful service. I also tried Stikkit, which is also shuttering it's doors, but must've just signed up for a beta or something because I don't remember much of the service. Had I put more time and effort into these services, I would likely be looking for alternatives. In an Open Source / Free Software world, I could take the code that I Want Sandy or Stikkit ran off of and find my own hosting. Because, however, these programs aren't Open Source / Free Software, the users have no options other than data exports. They are screwed, not only because they'll have to change their routines (and lets face it, software becomes part of your routine) and invest more time and energy in a new software product (or products, if you're like me) that may or may not serve their needs. Their time is again wasted.
So, what's more important to you? I prefer to use Open Source / Free Software because I know that I have options if something happens. I have the abilities (and if I wasn't as technical, I could find someone with the abilities) to download and modify the software to fit my needs. I don't have to care one whit about business decisions taking control of my software and shuttering it for good, and I have alternatives because most Open Source / Free Software products use open formats which allow migration from one platform to another if I decide to use another program instead.
Open Source and Free Software: Because your time is valuable.