Why didn't they just use hubot with the pagerduty script? hubot integrates into hipchat, pretty sure irc too, but maybe not. I would think writing that connector would have been easier than creating a whole new "bot" though.
We don't currently use Hubot internally. We've certainly thought about it, but we've also had chat bots at Stripe for a number of years (and writing a chat bot isn't actually that difficult), and consequently it's never been a clear enough win to port our existing stuff.
We would be more than happy to see someone port Pagerbot to use Hubot instead, though.
Not everyone wants to use hubot. I actually think having a communally maintained bit as part of an engineering group can be kinda fun, but to each their own.
We have a small team, and the cost can balloon depending on the number of pages you send, but overall it's worth it. One thing that makes it cheaper is having a phone that will repeatedly ping you with noise if you don't answer an SMS (you can send fewer pages for unanswered incidents if you have this.)
I had PD set up to attempt contacting me four or five times in a half hour by SMS and phone until I learned the service better. It also supports Android Push which seems to get delivered faster and also I believe has no incremental cost at PagerDuty. Now I also have a tablet that's usually in WiFi, so I get android push before the SMS goes out, and only need to get SMS when my tablet is out of WiFi range.
You're paying for the reliability, the integrations, and the excellent support staff. Just read the PD blog. They are obviously "top men" working at PD. We pay other services a good bit more per-annum and we usually see them going down all the time. PagerDuty pretty much stays up, and it works with everything.
That's great advice. Email & push are cheap for us, so they're free for you. SMS and phone are slightly more reliable but orders of magnitude more expensive, so 1 SMS and many push notifications can be the best of both worlds.
We do in fact have top men and women on our eng team if anyone is looking to join http://pduty.me/1DEFTuV
I'm on the sales team here at PagerDuty. Feel free to send me a note at mark at pagerduty dot com and we can work something out for your team regardless of size.