Being real, I don't think we will ever be able to confirm 100% that progress will stay from POB (pre-order beta) to launch. That said, we want to keep it! And we're pretty sure that any issues that arise that mean we have to wipe will happen pretty quickly So if you're concerned, take it easy for the first few days. Every day that goes without a wipe reduces the chance of their being one quite significantly. IDK if that makes sense. It does to me, but then I wrote it.
*Responding to how do we know that you won't wipe post-launch if you can't guarantee it now?*
It's the nature of things, hard to explain. We of course test and play and test and play every day, but until you put an environment like our service out to the public, you don't get the rigorous testing and data needed, but very very very very quickly when we put the service live on Nov 17 we will see volumes of data and info coming in like we've never seen before and it will very quickly show us what's right, and what's wrong. In those 13 days to launch, we'll have confidence in what's going on in the service. It's hard to explain, but we're certain that come the 30th, service will be as expected. Hiccups will come early in that 13 day window. It's a big part of why we're putting the beta out before official launch.