I have never heard of a SINGLE company that doesn't at least pay some kind of token allowance for on call then at least the hourly rate if responding to a call.
It is quite common and it depends on the role, as per my previous post even a CEO can get called out of hours and in most cases they're unlikely to get paid extra for it!
A senior account manager or "account director" can and will take calls on their mobile from clients at all hours, this is simply part of their job as is entertaining clients outside of work, sometimes this can be partly social sometimes it can be an angry client using a direct line to him to kick off about some issue they're having and get him/her involved, either way the client they have a relationship with phoning their mobile is not going to result in any additional token payments from the company (they're already earning a fat salary + bonus as it is)... they get their extra pay when that client re-signs an annual maintenance deal or pays for an upgrade or enhancement or some other project they've sold them.
Likewise developers (and dev mangers etc..) this is going to be super common in some startups, especially if something critical stops their product/app from working or website goes down etc... and at an early stage they might not have much in the way of a support team or, as the product isn't mature, the issues that the support team do encounter will require code fixes/are genuine bugs and not necessarily just require some techie following procedures, restarting servers or fixing some underlying issue outwith the company's product etc..
Also common enough in enterprise software that might be time critical for the client's business. Support guys get called all the time and get paid, developers/dev managers get called when something they're responsible for goes wrong. If they're already well paid then they can't necessarily complain too much, the attitude I've seen at a couple of employers has been essentially:
"If you don't want to get called then don't write **** code"
That is often true, in lots of cases the developer is getting called because of a mistake they've personally made/bad code they've written(sometimes it might be the case that something someone else has written is causing the issue with their stuff though). Also sometimes a techie/support person calls a developer for something that doesn't require the intervention of a dev resource or sometimes calls the wrong dev resource after misdiagnosing the issue but those things tend to become apparent rather quickly and only result in a short phone call + the techie who woke up the wrong person at 3am learns from the mistake or becomes very unpopular very quickly.
