Zygna have another problem..
Zygna isn't just dependent of Facebook, it is also dependent on a continuation of the the privacy violations that allow them to collect the data they sell (implied permission to collect data is not accepted under EU privacy law).
The problem is that data privacy is slowly on the return (as all trends, this one is reversing the "if you want privacy you must be a terrorist" brainwashing during the Bush/Blair era), and Zygna may be heading for a point where it will have to justify having all this data. I wouldn't want to be a shareholder when that happens..
IMHO, of course, but I see a few icebergs they're heading for.