The nature of the work that many of today's tech companies do--whether it's commodifying other people's time or recommending undergarments--requires them to rely heavily on users' trust

No one understands how hard this is better than Lynn Perkins, whose service, UrbanSitter, helps parents to find someone to look after their kids for the night. As any parent will tell you, earning their trust when it comes to their children is no easy task. 

Since Perkins co-founded her company in 2010, it has added 35,000 sitters and about 75,000 parents to its network, according to Fast CompanyIn a recent post on First Round Review, Perkins spells out some of her best advice for other companies trying to gain users' trust and experience similarly rapid growth.  

1. Avoid solely relying on the five-star system

Five-star ratings systems are an efficient way to get valuable user feedback quickly--especially for services like Uber, whose users typically won't spend more than a few seconds providing feedback. But Perkins learned that in UrbanSitter's case, it's necessary to provide additional metrics. 

"If I'm looking for someone last-minute, it's really good for me to know up front that someone with a great star rating might take longer than 24 hours to respond," Perkins tells First Round. So UrbanSitter provides parents with a look at sitters' average response time. The best part is that UrbanSitter's system can obtain this metric without having to bother users for any additional information.

2. Add a human element 

It's difficult for users to quickly get a full sense of the people they're interacting with on the other side of the system. The best solution is to let the service providers, in UrbanSitter's case the sitters, speak for themselves. So UrbanSitter added a video feature to let sitters introduce themselves. Perkins says that this helped to bring flat profiles to life. 

3. Try not to be too pushy 

Recommendation algorithms, like the ones Netflix uses to suggest new movies to customers, can be incredibly useful. But for something as personal as choosing a child care provider, it's best to cede control to parents, according to Perkins. 

So rather than tell users that they'd enjoy a particular product, allow them to use search filters to uncover what they came to your site for. Additionally, advises Perkins, "If they know what it is they're looking for, make it easy for them to find it." 

4. Be proactive

This last tip comes from Perkins's experience using ZipCar. One time when she had a reservation with the car-sharing service, a driver got into an accident a half hour before she was scheduled to use the vehicle. ZipCar called her to let her know, directed her to the closest ZipCar station, and allowed her to rent a more expensive car for the same price. The bottom line: You'll earn your users' trust if you have a good plan B at the ready when something goes wrong.