I think it's crazy that the SLA just gives you a credit. Even worse! In the contracts I've seen, you have to prove the duration of the outage and sometimes even that there was commercial impact using your own monitoring. What a pain in the ass.

It would be easy for me to tell my customers exactly what they need to say to get the maximum, but I've been told not to do that, so I guess it's on them to figure it out.