LeBron James -- Generating Big $$$ For Local Biz's ... 'We Should All Kiss His Ass'

LeBron James is a 1-man stimulus package in Cleveland -- with several businesses around the Cavs arena telling TMZ Sports they've been CRUSHING IT during the playoffs ... and they're all crediting #23.

Don't forget, the Cavs didn't make the playoffs once during the 4 years LeBron was in Miami -- which means 4 years of low foot traffic for the restaurants and stores near Quicken Loans Arena.

But with this year's run, Cleveland has already hosted an additional 7 playoff games (with more to come) ... and the 8 establishments we spoke with say the extra business has been HUGE.

Here's what a few of the owners and managers told us.

"Every business owner, hotel, restaurant, grocery store owner ... anyone who owns a business in downtown Cleveland should be kissing [LeBron's] ass, including me."
-Owner, Zocala Mexican Grill

"It's certainly a nice bonus for local businesses and we are happy to have LeBron back here. On the day of home playoff games, I'd say business increases by more than 40 percent."
-Manager, The Greenhouse Tavern

"We just opened in the beginning of the year. One of the reasons we came to downtown Cleveland is because of the downtown boom, and a lot of that's LeBron James being back in Cleveland."
-Owner, A Bar + Kitchen