In just a year and a half, e-retailer Dot & Bo has grown from a handful of employees to more than 80. The San Francisco company, which sells retro-style furniture, hip knickknacks and chic home decor through its website, is booming. As Dot & Bo grew, it needed help onboarding new hires. CEO and co-founder Anthony Soohoo turned to another fast-growing San Francisco startup, Zenefits. Less than 18 months old, Zenefits provides HR administrative services at a price even the most cash-strapped company can afford: absolutely free.