Omar Mumin, a former Uber driver who now works for a competitor, Lyft, told CBC News that it's really tough to break even.
Uber drivers are not allowed to accept tips and they have to pay for their own vehicles, maintenance and gas.
Mumin says he has started a union with 500 members from both companies, and says they are willing to take job action to fight for better wages.
"I hear from drivers, now they have to work 14 to 18 hours just to break even," said Mumin, now president of the Seattle Ride-Share Drivers Association.
Cabbies rail against 'new wave' taxi
As in Vancouver, Uber has also been criticized by the union that represents Seattle cabbies, who claim they are facing competition from a company that operates under more favourable conditions.
"They kind of feel like they've been following the rules, they've been toeing the line all the time," said Dawn Gearheart of Teamsters Local 117. "And now they're in a position where they're competing with a totally unregulated, new wave taxi."
Still, the working conditions offered by Uber are appreciated by some drivers.
Selam Alula, who moved from Ethiopia to Seattle, drives for the new company, which she says gives her total control over her hours.
When she wants to work, she turns on her phone and she's on the clock. To punch out, she turns it off.
Nevertheless, she says, safety is a concern.
"Because I'm a woman. If it's at night, you never know," she said. " I always say, 'what do I have for backup?'"
Uber says its thousands of drivers in the city are well paid and well treated—and that there is an emergency contact line in place.
"We've always been a business that's been very centred around the driver," Brooke Steger, general manager of Uber Seattle, said. "In the Seattle office, we have driver office hours three times a week. We also have a live text line available to all the drivers in case of emergency."
Seger said Uber also runs checks on drivers in order to ensure passenger safety.
"Every driver is background checked. A full, comprehensive background check is often better than what the existing city, state or country has been doing," he said.
"Before a driver goes on the system, their criminal history is checked, if they have any kind of sex offender record, that's always checked, as well as their driving record."
Cheaper, convenient service
Seattle residents told CBC News they liked the service for its cheaper fares and the fact that no money actually changes hands.
Uber was run out of Vancouver two years ago after the Passenger Transportation Board ruled it had to charge a minimum $75 per trip, and the company refused.
On a mission to return to the city, Uber has already started posting Vancouver jobs, despite the fact that city council voted last week to impose a six-month moratorium on issuing new taxi licences.