After using it for several campaigns, I can testify that it's a very efficient tool. I just ran a new campaign which got a x4.25 viral multiplier.
It's one of the best platforms on the market, with an amazing feature set. (I compared it to KingSumo, UpViral and Gleam.) And the platform is constantly improving.
So far, it's lacking updated documentation / tutorials, so the learning curve is sometimes steep. But the support via chat is awesome. (Thanks James!)
Looking forward to getting all the goodness upcoming in the roadmap!