How does this service differ from ifttt? Why would I want to use it in place of ifttt?

I see that you have a paying account, which is nice - ifttt has limitations (limited number of accounts, etc.) that limit its utility for me (and I'd certainly pay for those things).

I see you have an API, which is really handy for dev-minded types. Can I build things that plug in as triggers or actions in an "ad-hoc" manner - things that are only for my use, and not advertised to other users? That'd be pretty incredible.

I only wish the hardware I acquired recently to work with ifttt - my WiThings body scale and WeMo Belkin outlet/sensors - were compatible. I'd like more complex rules involving them.