NEW YORK — Amazon’s website ran into some snags quickly Monday on its much-hyped Prime Day, an embarrassment for the tech company on the shopping holiday it created.

Shoppers clicking on many Prime Day links got only an abashed-looking dog with the words, ‘‘Uh-oh. Something went wrong on our end.’’ Many took to social media to complain that they couldn’t order items.

It wasn’t clear how widespread the outage was on one of Amazon’s busiest days of the year, but the hiccups could surely mute sales and send shoppers elsewhere. A company spokesman didn’t immediately respond to an e-mail.

Amazon, which recently announced that Prime membership would be getting more expensive, was hoping to lure in shoppers by focusing on new products and having Whole Foods be part of the process.


While Amazon doesn’t disclose sales figures for Prime Day, Deborah Weinswig, CEO of Coresight Research, had estimates it will generate $3.4 billion in sales worldwide, up from an estimated $2.4 billion last year. Prime Day also lasts six hours longer than last year.

Shoppers, meanwhile, have lots of sales to choose from as other retailers offer promotions to try to take a share of the spending. Chains like Macy’s, Nordstrom, Best Buy, Walmart, and Target planned to roll out their own promotions, said Charlie O’Shea, lead retail analyst at Moody’s.

‘‘Brick-and-mortar retailers know that they have little choice but to continue offering their own deep discounts, which is evident in the proliferation of ‘Black Friday in July’ deals that are being launched earlier each year, as well as various ‘price match’ offers,’’ he said in a note Monday.

Amazon created Prime Day in 2015 to mark its 20th anniversary, and its success has inspired other e-commerce companies to invent shopping holidays. Online furniture seller Wayfair introduced Way Day in April, becoming its biggest revenue day ever.


Prime Day also usually helps boost the number of Prime memberships. Amazon disclosed for the first time this year that it had more than 100 million paid Prime members worldwide. It’s hoping to keep Prime attractive for current and would-be subscribers after raising the US annual membership fee by 20 percent to $119 and to $12.99 for the month-to-month option.

Meanwhile, Amazon workers, who have long gone on strike in the run-up to the holidays, have found a new occasion to get their employer’s attention: Prime Day.

Nearly 1,800 Amazon workers in Spain went on strike Monday. Thousands more Amazon employees in Poland and Germany are expected to walk off the job on Tuesday, the second day of the 36-hour sale, for similar reasons. The unions that represent the warehouse workers, Comisiones Obreras and Verdi services union, say they are calling for better working conditions, pay, and health benefits.

‘‘The message is clear — while the online giant gets rich, it is saving money on the health of its workers,’’ Stefanie Nutzenberger, a spokeswoman for Verdi, which represents German workers, said in a statement on its website.

This week’s labor protests underscore a growing challenge for Amazon: It is facing increased scrutiny over its hiring and labor practices at a time when it’s looking to add thousands of new warehouse workers and growing at breakneck speed.

In the United States, advocacy groups are planning a series of consumer rallies outside of Amazon-owned Whole Foods Market locations to protest the sale of Nazi, confederate, and white nationalist merchandise sold through Amazon’s marketplace of third-party sellers. There have also been widespread calls on social media for shoppers to boycott Amazon during Prime Day, which this year began Monday afternoon and continues through Tuesday.


Amazon and its billionaire founder, Jeff Bezos, have a long history of thwarting unionization efforts in the United States. (Bezos also owns The Washington Post, where last week unionized employees approved a new contract with the company after 14 months of tense negotiations.)

On Monday, Bloomberg reported that Bezos is now the richest person in modern history. His net worth broke $150 billion in New York on Monday morning, according to the Bloomberg Billionaires Index. That’s about $55 billion more than Microsoft Corp. co-founder Bill Gates, the world’s second-richest person.

In Europe, where unionization is more widespread, labor unions have been on the front lines of calling for workers’ rights at Amazon’s warehouse facilities, where physical demands can be grueling and temperatures can reach extremes. Until now, though, most of their efforts have been centered around the critical holiday season. Last November, for example, hundreds of Amazon workers in Italy and Germany went on strike, saying they were under ‘‘high pressure to create more and more in less time.

A spokeswoman for the Seattle-based giant said it was committed to providing workers with ‘‘positive working conditions.’’

‘‘Amazon is a fair and responsible employer and as such we are committed to dialogue, which is an inseparable part of our culture,’’ spokeswoman Melanie Etches said in an email.


This week’s strikes have also inspired widespread calls for shopper boycotts on social media platforms such as Twitter.

This year’s Prime Day is expected to bring in $3.4 billion for the company, up from an estimated $2.4 billion a year ago, according to retail research firm Coresight Research.

Material from The Washington Post was used in this report.