Star file photo Niles Main Street is encouraging shoppers to “cash mob” downtown businesses March 24. Mobbers must spend $20, meet three people they have never met and have fun.

YouTube has made “flash mobbing,” where people gather in a public place for a surprise performance of a dance or song, a household name.

But have you heard of “cash mobbing?”

In an effort to support local business, the new nationwide trend is to cash mob a store. People will gather at a particular store at a set time and spend at least $20 there.

Niles Main Street is introducing its own version of National Cash Mob Day March 24.

Niles Main Street Director Lisa Croteau said while many communities focus on a single business, Niles Main Street is inviting the community to mob all downtown Niles merchants.

“As a district, it’s hard to pick just one business,” Croteau said. “So we’re letting people choose who to mob.”

This creates some healthy competition between downtown businesses, Croteau said.

Croteau is encouraging downtown merchants to post on Facebook reasons why people should mob their store. The Niles Main Street page is reposting all cash mob-related posts.

Those who participate in the cash mob can post their experience on Niles Main Street Cash Mob Facebook page and be entered into a drawing for $40 in “downtown dollars.”

“I think it will be fun,” Croteau said. “I guarantee people will find something they didn’t know was here.”

Croteau said there are three rules for cash mobbing: spend $20, meet three people you didn’t know before and have fun.