SPOKANE, Wash. – Have you ever noticed that there are a lot of mattress stores around the Spokane area? Have you ever wondered why?

Spokane's North Division Street is six lanes of asphalt flanked by businesses. You can buy everything from fast food to a new Ford all under the watchful eye of Bigfoot.

There's something else about North Division. On just one stretch of the road, you will find more than a dozen spots to buy a mattress. Some stores are practically a stone’s throw from another, but why?

In order to answer your question why are there so many mattress stores, we set up an interview at the Mattress Firm on North Division. Trouble is, we were supposed to go to the other Mattress Firm a couple blocks up.

There are four Mattress Firm stores on North Division alone. District Manager Amanda Vent tells me we're not the first to miss the mark. Mattress Firm has 13 stores across the Inland Northwest plus 10 more in Central Washington.

"I think the last time I checked there's like 267 mattress stores in Washington," said Ryan Leaf from Mattress Depot.

Leaf just added two Mattress Depot stores to the mix, one is on Spokane's South Hill.

"Mattress Firm is just down about a mile from here. Big surprise right," said Leaf.

His second location in Spokane Valley is strategically located within a three mile radius of seven or eight other mattress stores.

"When I started talking to the broker he goes, ‘Spokane's notorious for mattress stores and gun stores.’ They like their guns and they like to sleep apparently," said Leaf.

Mike and Melanie Davis like sleep, but their mattress is doing that sag-in-the middle thing. Now, they're on the hunt for something new.

"And sure enough there was like three right in a row," said Melanie.

Why three in a row? Because people are buying. KREM 2 consulted industry researcher IBIS World. Their research shows mattress industry revenue in the US soared from about 7 billion in 2010 to more than 9 billion in 2016. One key reason is that it is riding the coattails of a stronger housing market.

"As people are buying more houses and moving, we definitely see an uptick in our business," said Vent.

IBIS points out growth is also fueled by the fact we simply have a deeper understanding of the importance sleep. And really, when you buy a mattress most people want to try before they buy.

"In this day and age it's one of the few businesses that's protected from the internet," said Leaf.

"We have an ongoing joke that the first 20 minutes of your nap is free," Vent joked.

So is the market saturated or is the mattress bubble about to burst? The representatives KREM 2 spoke with don't think so. They are so confident both of their companies are planning even more stores in our region.

You have probably seen the mattress marketing that says "replace every 8." The National Sleep Foundation calls that the typical lifespan, but not every mattress is the same. KREM 2 spoke with the manager of Northwest Bedding who offered this simple guideline: If you wake up and you hurt it's time to replace your mattress, whether it is a year old or 30 years old.