Oh cool, I didn't know if others were doing this. I've recently just started going down this path with some zero effort IFTTT triggers but I'm not happy with how infrequent they seem to trigger. My next step is to build my own set of listeners/scrapers.
I posted the same thing on a similar thread yesterday but if you're looking to build some scrapers and listeners and make it easy for yourself I'd highly recommend Huginn (https://github.com/huginn/huginn). I set it up a few months back and I've been using it to scrape all sorts of info and alert me on things. IE:
* A change in GBP -> NOK exchange rate, to indicate if it's a good time to buy ready for my next trip to Norway.
* Alerts on flight prices to help me purchase flights when they're at their cheapest.
* Daily digest email with content I'm interested in from HN and some web comics.
* A summary of new content coming into my RSS reader.
It works really well for this sort of stuff and I found it fairly easy to get up and running.