Yes. If you are running in two zones in the hopes that you will be up if one goes down, you need to be handling less than 50% load in each zone. If you can scal

Yes. If you are running in two zones in the hopes that you will be up if one goes down, you need to be handling less than 50% load in each zone. If you can scale up fast enough for your use case, great. But when a zone goes down and everyone is trying to launch in the zone still up, there may not be instances for you available at that time. Our site had a billion in revenue or something based on a single day, so for us it was worth the cost, but it not easy (or at least it wasn't at the time).