This fast-food chain taking over America has an exclusive club - but you have to eat salad every day

The most exclusive club in the fast-casual industry requires spending thousands of dollars a year - on salad.

Sweetgreen, the restaurant chain with 43 outlets in cities including New York and Boston, routinely draws lunchtime crowds and the kind of customer loyalty that any retailer would envy. 

One factor behind all this - in addition to an app and clever marketing - is a loyalty program that, at the highest level, has impossibly high standards. 

Membership to the cult of Sweetgreen has some major benefits: concert tickets, swag, an abundance of leafy greens. But, it also requires spending some serious cash.

If you want to reach the most exclusive tier of the salad chain's rewards program - or "black status" - you need to spend at least $2,500 a year. 

Let's break that figure down. Two thousand, five hundred dollars a year means spending $6.85 a day, every day, with no breaks for holidays, sick days, or days where you may simply not want to eat another salad. It means spending almost $50 every week, at the chain.

Assuming an average cost of $11 per salad, you have to eat more than 227 Sweetgreen salads in a year.

"At this point, you're essentially family to us," the Sweetgreen website states. "We know you by name + salad and may have even met your parents."

Of course, reaching black status has its benefits.

Black status members get free access to Sweetgreen's annual Sweetlife music festival (either two lawn tickets or one VIP ticket). Or, they can skip the festival, and throw a 10-person party at their local Sweetgreen.

They also have status to a "Sweetgreen concierge," an "exclusive customer service email for VIPs only." Apparently, spending more than $2,500 at the chain means you can expect a better level of service, with the company website saying, "you deserve it."

If you aren't ready to commit to a diet dominated by salad for the next year, you can set your aim lower, to the lesser levels of Sweetgreen's rewards program.

Gold status requires spending $1,000 a year (a measly $2.74 a day). Once you reach this level, the company promises it will send you surprise swag and offer access to invite-only tastings and previews.

Then, there's the entry-level green status, which requires spending just $100 a year. Your reward: a free salad on your birthday and 1% of all your app purchases going toward the company's charity, Sweetgreen in Schools.

"We wanted to integrate lifestyle into a loyalty program to further connect with our customers and help them connect to their community and values, aka live the sweetlife," cofounder and co-CEO Nathaniel Ru told Business Insider. 

Clearly, living the "sweetlife" requires some major investments in salad.