It's always interesting to me when people build on top of a service that is free with no guarantee of it existing in the future. 4 years ago I wrote a tiny bit of code to play (it was so simple it can barely be called that) with a framework I came across. It simply took a zip code, looked it up in a sqlite DB and then spit back city/state. If you already had a backend you were better off just taking the sqlite DB and adding it or it's data to your own code (It's all on github but I won't link because it's not something I'd ever want to showcase). I threw up a website to play with it and without any effort on my part people started using it. I assume they found it through my github but I can't be sure.

I've received more emails over the years about requesting features (JSONP/CORS) and asking questions about it than any other piece of work I've open sourced. The code is literally 50 lines of custom code and could probably be less than 20 if I was writing it today, hell it could be less than 50 lines total (no framework needed) yet it is the most starred/most used thing I've written and made publically available... It gets about 4 million hits a month and I'm sure it being used in production environments in some places which blows my mind but I don't care enough to add logging to check where. It's on a shared host that I've had since I got started and since I have a number of my own tiny sites and sites I've hosted for friends/family It's costs is pretty much $0, the only cost is renewing the domain name and at this point $10/yr is worth not dealing with pissed off people (even if it was free and had no guarantee of service).