Amazon’s website has been experiencing issues for hours now due to heavy online traffic on Prime Day, the e-commerce giant’s made-up holiday designed to boost sales. According to DownDetector.com, Amazon has been experiencing issues since around 3:05PM ET today, with a large spike in reports immediately after Prime Day officially began at 3PM ET / 12PM PT.

It’s not clear how widespread the outage has been. According to DownDetector, the outage is restricted to the US, and it appears to still be affecting large parts of California and the New York as of 5:30PM ET, with a smattering of smaller outages in the Pacific Northwest and other parts of the country.

Some users have reported being able to access product pages but not the Amazon.com homepage. Some are not experiencing issues at all, while others are seeing the company’s well-known “dogs of Amazon” page, which is the company’s placeholder art during full-blown outages that highlights well-known pets of Amazon employees.

amazon down on prime day heellpp #AmazonPrimeDay pic.twitter.com/IQRpr72iDw — Lisa Scherzer (@lisascherzer) July 16, 2018

Bad news: Amazon seems to be crashing from demand for Prime Day sales. Good news: Amazon's error page is amazing. pic.twitter.com/lhUcipHTZX — Seth Fiegerman (@sfiegerman) July 16, 2018

Another common issue that appears to be popping up for the users that can get Amazon’s website to load is a never-ending loop between the homepage and an incomplete deals page. In that situation, clicking on the “Shop All Deals” button takes you from the homepage to another, similar-looking page that prompts you to click the same button again, which will then take you back to the homepage. Another issue is users being able to load items into their shopping cart, but the shopping cart empties itself immediately.

Currently experiencing a never ending loop of "Shop All Prime Deals" on @amazon, is anyone else seeing this loop too? #PrimeDay2018 pic.twitter.com/OO9GXBbIl1 — Meghan Anders (@m_anders89) July 16, 2018

In a statement released at 5PM ET, Amazon acknowledged the issue for the first time, writing on Twitter that “many are shopping successfully” and noting that there are still 34 hours left for Prime Day deals. It appears the company’s website is now functioning normally for some users while Amazon works to resolve the issue, though many are still reporting issues with adding items to their carts, checkout, and just getting into the deals portal from Amazon’s homepage.

Last year, Amazon’s Prime Day generated an estimated $1 billion in sales from the 30-hour event, which roughly equates to around $34 million every hour. Other estimates put Amazon’s Prime Day haul closer to $2.8 billion, which would mean almost triple that revenue amount per hour.

Regardless, it’s safe to assume Amazon is taking an outage like this very seriously — not just because it looks bad, but because there is significant financial incentive to make sure every minute of Prime Day can result in a maximum number of completed orders. According to Internet Retailer, this year’s Prime Day is projected to earn Amazon $4 billion in sales, so long as the site is up and running.

Update July 16th, 3:43PM ET: Added additional information about the outage and Amazon’s Prime Day revenue history.

Update July 16th, 5:20PM ET: Added statement from Amazon.