I am wary of building on top of any third party web service, but I free services like this I may play with but never depend on for personal or business use.
I've upvoted you, but I really want to second this verbally too. I don't see any adverts on IFTTT (and even if they were: once setup, I wouldn't be visiting the site often and seeing them), and don't understand how they're monetising. This is a service I'd really like to use, but I don't want to come to depend upon it, then find it folding (either due to monetary problems, or acquired by a third party and being shut down).
Some information on how they intend to stay alive would be fantastic.
I wondered about that too, and one thing that occurred to me was that if they get popular, they've got access to combine data about their users across all the source and sink services the users use. That is, they can get all my readily available Facebook data (friends, likes, etc.), my Twitter feed and follower/followee/favorites lists, etc.
I doubt IFTTT is doing such data fusion today (their userbase is probably too small to make it worthwhile), but I wonder if that's the eventual plan. To advertisers, that sort of data could be immensely valuable for ad targetting.
My first reaction was that businesses would use this to do systems integration (send an email every commit, add a note in group chat before a meeting, etc.) These are already pretty easy to wire, but there's value in going from easy to trivial...
I am wary of building on top of any third party web service, but I free services like this I may play with but never depend on for personal or business use.