The U.S. Postal Service has been financially besieged for years, and unless Congress acts, the independent agency could run out of money by 2021. Now, there are calls on social media to save the USPS by buying goods from its online store.

The site has everything from screen-printed Marvin Gaye posters to 1970 Plymouth Hemi Cuda muscle toy cars. The runaway hit by far, however, has been a long-sleeve crop top showing a stack of five envelopes. The crop top is sold out, to the chagrin of many.

Kayla Miller of Pittsburgh managed to get one of the crop tops after seeing a tweet about the store. While she rarely buys mass-produced clothes because of the environmental cost, she felt like she was doing something tangible for the Postal Service and reminding others about the service's crisis.

"This is the kind of thing I feel like it's so easy to just let someone else worry about or forget about, and I don't want to forget," Miller said. "Plus, I get a cute new shirt!"

Most items are connected to stamps, said Sara Martin, a senior public relations representative for the organization.

"This could range from small toy vehicles, to puzzles and apparel," she said. And there are other shirts, like the sweatshirt commemorating the 100th anniversary of airmail and a shirt showing Mr. ZIP, a character created by the Postal Service in 1963 when ZIP codes were introduced.

There are other efforts to help the service. Earlier this year, there was an online campaign to encourage people to buy stamps, Change.org has a petition and the Postal Service is creating memes to promote letter writing.

The service has become a political lightning rod because of the crucial role it may play in the presidential election. David Hogg, an activist, tweeted to his million followers to shop at the Postal Service store, calling it a way to help the Postal Service financially and "make sure everyone can vote this election!"

But it's going to take more than selling tote bags to save the service. Groups like the American Postal Workers Union (APWU) proposes to expand the services the post office can offer, including check cashing, selling hunting licenses, providing Wi-Fi and becoming electric car charging stations.

"There are so many things that the post office could be and should be," said Mark Dimondstein, the president of APWU.

Dimondstein isn't surprised by the spontaneous support. A recent Pew Research poll found that 91% of Americans had a favorable view of the agency, and another survey found the U.S. Postal Service to be the most essential business during the pandemic. People, Dimondstein said, want to support a service that they like and need.

"The post office is an iconic part of the country," he said. "We all use it differently, but we all use it."