Are the sites hosted on a cloud based platform where we can scale up and down based on demand?
If not then Heroku is great for this sort of thing, though we might wan to consider one of the more recent open and more portable alternatives.
I've used Heroku in my day job to effortlessly scale up when we've suddenly had 100x traffic and then back down when that traffic slows or drops off. You can scale up Heroku dynos within minutes with one line in the terminal and as such increase/decrease your capacity at will. There are some third party services that will automate this process too.
The fact that the main Bitshares.org site is built using Wordpress does not make me hopeful that we have this capability as PHP based systems that require write access to the host don't play well with services like Heroku.