It's a simple, clever idea. ESPN generates notifications for a number of different things you might care about: when your country wins a medal (or just a gold medal); when a record is broken; when a search term of your choosing fires; etc. IFTTT then forwards that notification to wherever the heck you want, from Facebook to Twitter to your phone's notification bar. You get the feed you want, where you want.
This may well be IFTTT's killer app (or at least, an illustration of it). The thing is, each individual notification channel is easy enough: companies build these sorts of notifications all the time. But as one-offs, they're a pain in the ass both for the company and the consumer -- lots of reinventing the wheel, and extra sign-ins. But if I'm already signed up for IFTTT, it's trivially easy for me to add one of these feeds: easy enough that I might do so, and I don't even *care* that much. IFTTT means that you can add *one* API, and get notifications for *dozens* of services.
Neat stuff, and illustrative of the tool's power. My sense is that IFTTT is one of those key infrastructure tools (one that I'm likely to want for Querki, if and when it's successful enough). This is a good illustration of why -- it has network effects out the wazoo...
ETA: Okay, what the heck -- it's an excuse for me to try out Pushover, and do something real with IFTTT. Here's my recipe.