After a rocky start, Amazon ended its fourth Prime Day on a high note. Sales from its 36-hour shopping extravaganza surpassed those from Cyber Monday, Black Friday, and last year's Prime Day, making it once again the biggest shopping event in Amazon's history, the company said.

Small and medium-size businesses notably crushed the day, collectively making over $1 billion in sales, according to Amazon, which declined to disclose last year's sales number. After adjusting for the extra six hours--the sale was just 30 hours long in 2017--the ecommerce giant saw a 24 percent uptick in sales and total orders rose 18 percent compared to last year's Prime Day, according to data from Feedvisor, a pricing software tool. 

For many small-business owners and entrepreneurs, Amazon has become one of their most valuable sales channels. The heightened attention Prime Day delivers, in particular, has helped entrepreneurs create awareness around their brands and grow their businesses--and the past 36 hours did not disappoint.

Amazon Delivers

"We saw more than 60 percent increase [in sales] from the best day we've ever had," says David Simnick, co-founder and CEO of Soapbox, a soap and shampoo maker in Washington, D.C. Simnick tells Inc. that this year his company ran coupons available for all Amazon customers.

Instead of focusing exclusively on Prime members, who pay Amazon's $119 annual subscription, this year Soapboax opted to leverage the flood of onlookers shopping for bargains and expanded its pool of potential customers.

New brands like L.A.-based nutrition startup Truwomen, which only launched a month ago, not only saw high demand for its products but experienced a significant uptick on its Instagram following. The company tells Inc. it now has more than 11,000 followers, up from 4,000 two weeks ago.

Similarly, Seattle's Tomofun, makers of the Furbo dog camera, saw its Instagram account grow by 10,000 followers in the past few days. The company has also been running influencer campaigns on the social-media platform in anticipation of Prime Day, so some of the growth is a reflection of that, says Maggie Cheung, Tomofun's co-founder and chief marketing officer.

No matter the direct cause, the uptick has been remarkable, says Tomofun co-founder and CEO Victor Chang. In the first 15 minutes of Prime Day, Tomofun sold 500 units of its Furbo dog camera. Chang added that last year the company ran out of stock in the first six hours. "[This year,] we tripled our inventory and our sales have more than doubled," he says.

"Primed for Prime Day"

The shopping holiday has exploded in popularity since it was first introduced in 2015. Even competitors like Target and eBay are running concurrent "Black Friday in July" sales to cash in on the action.

Customers are "primed for Prime Day," says Kelly Rundle, founder of Simply Sales, a company that helps Amazon retailers sell on the platform. Indeed, traffic was so overwhelming in the first few hours of Prime Day that the website was temporarily unavailable. The technical glitch did not seem to deter sales, however, and none of the sellers Inc. spoke to experienced any significant decline.

Prime Day's hype also means that consumers are adjusting their shopping habits accordingly. A few of the businesses interviewed reported an unusually low sales performance on the week before Prime Day, which could signal that shoppers are actively holding off in anticipation of the promised bargains. All of the businesses that reported this instance, however, said that the sales generated on Prime Day more than made up for that bad week.

Over all, Amazon sold more than 100 million products worldwide on this year's Prime Day, which included discounts on Whole Foods and was open for the first time to additional markets like Australia and Singapore. Its Prime service currently boasts more than 100 million members.