Keep in mind that the account growth does cover 3 free services now: IPv6 tunnels, Certifications, and the DNS service. We have a good number of users registering for access to one or more of the available free services. As we refine existing & add new services, we absolutely hope that we attract more and more users
The only service that could potentially saturate would be the tunnels, but that hardware has the capability to have multiple bonded interfaces, or 10G interfaces (that'd be awesome!), so that resolves any kind of capacity issue with a quick configuration and minimal interruption. We are also actively working on expanding our IPv6 allocation.
We don't see a problem with keeping up