Denny’s has around 1,500 restaurants across the country, and all but one – a franchisee in California who’s exiting the business -- are participating in the promotion, CEO Nelson Marchioli told me.

I asked Marchioli if there were any strings attached to the offer, such as a minimum purchase requirment, and he assured me that there weren’t. But there are a few things you need to know. The deal is technically good only for meals eaten inside the restaurant, not takeout orders. But Marchioli says he’s authorized managers to issue rain checks for customers who’d like to take advantage of the deal, but can’t stay. 

The promotion has a strict no-substitutions policy, though you can request, at no extra charge, Egg Beaters instead of the real deal. 

Denny’s is expecting the promotion will draw as many as 2 million incremental guests, a 550 percent increase over the chain’s typical customer count on a Tuesday.

Why is the chain serving up such a generous portion of hospitality? “In these economic times, we all settle for fast food, and I wanted to remind America that Denny’s is a great value,” Marchioli says. "We talked about several types of offers, but at the end of the day, free works. We’re throwing a party and want everyone to come.”