The CEO explicitly says that this is a response to ADP:
> As Conrad tells it, a select group of Zenefits employees holed up in the Courtyard Marriott to start working on a secret project to create a payroll system shortly after paycheck services giant ADP cut the company off earlier this year.
> “We’ve been working on this basically since the day we started getting blocked by ADP,” Conrad told TechCrunch.
I would have probably been working on it before that, if I were them, as I don't ever feel comfortable being a sharecropper on someone else's land. But, they've delivered quickly.
> As Conrad tells it, a select group of Zenefits employees holed up in the Courtyard Marriott to start working on a secret project to create a payroll system shortly after paycheck services giant ADP cut the company off earlier this year.
> “We’ve been working on this basically since the day we started getting blocked by ADP,” Conrad told TechCrunch.
http://techcrunch.com/2015/11/16/zenefits-launches-its-own-p...