ZenPayroll’s round included Box CEO and co-founder Aaron Levie, Yammer CEO and co-founder David Sacks, Dropbox CEO and co-founder Drew Houston, YouTube co-founder Jawed Karim, Yelp CEO and co-founder Jeremy Stoppelman, Badgeville CEO and co-founder Kris Duggan, SugarCRM CEO Larry Augustin, and Zuora CEO and co-founder Tien Tzuo, as well as Google Ventures, Data Collective, Sherpalo Ventures, and Salesforce.com. Although unannounced until today, the company closed the round in April, following its graduation from YC.

Interestingly, ZenPayroll raised nearly $1 for every US business than needs payroll services – more than 6 million of them. Needless to say, it’s a big market, one dominated not by 800 pound, but by 800,000 pound gorillas. ADP. Paychex. Intuit. Combined, they represent $50 billion in publicly traded market cap.

A SIX MILLION DOLLAR SEED ROUND?! MOTHER OF GOD!!!