Vantaggi
Pay is the biggest perk, $12/hr in New York City (I can't speak for other cities). There is ALWAYS something to do, depending on the location where you work and what department. Women's department is hectic and the busiest, but you never just look around for work or pretend to be busy. There is possibility of moving up, since the company openly hires from the inside before hiring outside higher positions. Also, you meet great people!
Svantaggi
Stores are mismanaged. There is no communication between departments and between employees and managers. Schedules are almost always messed up, so you have to go through the process of playing telephone with managers and looking for someone to take your shift. Employee discount is terrible, only 15%, and that's after 3 months of working. Speaking of promotions, most of the people holding corporate or high paying jobs in ZARA are all from Spain. Maybe it's just because I work near the corporate office in NYC, but it is true.