Maybe you've seen the ads on Facebook or other places online. The online retailer Zulily is putting pressure on its biggest competitors, offering a new "Best Price Promise,” just in time for the holidays.

If you haven't heard of Zulily, don't worry, many people haven't, despite it being in business since 2010. I found the website very clean looking; products didn't overwhelm the page, just large clear photos of what's on sale. And most of what you find on the front page is on sale. Zulily has a new sale every day on clothing, toys, home goods that last about 72 hours. To shop there though, you must give them an email address and sign up for an account. You can't window shop as a guest.

"Best Price Promise" is where they'll match any price found online. On some products, they'll even show you the best price they found at Amazon or Walmart.

To check that out, I looked at a trendy weighted blanket. Name brand: Puredown. $34.99 on Zulily and it claims to have found a similar item on Walmart for up to $120. I found dozens of similar items at Walmart for a similar price of 35-dollars. The exact brand and size is $74 at Walmart at $110 at Amazon. Later I found it on sale at Amazon for $74.

Keep in mind though, that's one of Zulily's sales of the day, similar to Amazon's Deals of the Day, so you'd expect a lower price.

I found Zulily to be competitive with Amazon and Walmart prices on day-to-day items. Searching by category and looking at items that are not part of the 'sale' that day, prices were similar if not a dollar less.

Zulily does not sell TVs or many name-brand appliances like Kitchen Aid, at least they didn't have any listed in those categories Wednesday morning.

Ordering is simple and you can pay through PayPal, but you'll also pay about $7.99 for shipping. To save money on shipping you have a few hours to order more items and Zulily will try to put multiple items in one shipment. If you do not like a product, you can return it, but returns are for store credit and they'll deduct another $8 for shipping and handling the return.

A Zulily spokesperson told me the new best price guarantee applies to full-price items so it will not include CyberMonday and Black Friday specials at other online retailers.