As I mentioned I just found the link in the venturebeat article, ask their CEO for more data.
About half of the numbers are redacted, but you can see if it's a single digit or a double digit number. And you can read in the 2015/2016 plan on page 10:
* 3x sales headcount and rapidly race towards distribution
* Reduce sales ramp time by 30-50% via sales enablement
* Double headcount every 6-9 months
It doesn't add up with the "He confirmed to TechCrunch that 18 people were laid off, mostly in sales"
presentation (2014): http://www.slideshare.net/metrics1/mixpanel-our-pitch-deck-t...
original source of the news: http://venturebeat.com/2016/01/08/mixpanel-starts-2016-with-...