They have not seen blistering growth since. They haven't grown much at all in two years, since the initial burst of growth early into their existence. The clock is ticking on Vox, they either have to generate substantial growth soon, or they're guaranteed to go under (these new media sites are universally red ink machines, betting on continual capital investment to try to get a lot larger, then the growth stops but the red ink continues and they go under, same business concept failure repeating over and over again).

Their traffic is directly measured:

https://www.quantcast.com/vox.com