One Prime Day apparently isn't enough anymore.

Amazon (AMZN 3.49%) surprised the market and delighted its most loyal customers in September when it announced a second Prime Day this year. Started in 2015, Prime Day is the annual shopping extravaganza designed to drive membership for Amazon Prime, the company's loyalty program that now has more than 200 million members.

Amazon touted the second Prime Day, which will be held Oct. 11-12, as a way for members to get early access to holiday deals from brands like Peloton Interactive and New Balance. On the surface, the latest Prime Day may seem like it has the same intentions as it normally does, but a look at Amazon's most recent earnings report offer some hints as to why the company is running the shopping bonanza for the second time in just three months.

Amazon isn't immune

The retail industry has been plagued by excess inventory this year as big-box chains and others overstocked merchandise to absorb supply chain delays and as they expected the pandemic-era shopping binges to continue. However, the supply chain constraints have eased, and consumer spending shifted to services like travel and restaurants as pandemic restrictions relaxed.

Walmart and Target both reported profit declines due to bloated inventory levels, and even Nike said it would have to aggressively mark down merchandise after inventories rose 44% in its most recent quarter.

Amazon didn't get the same level of scrutiny as its retail peers, but the e-commerce giant's inventory jumped 58% year over year in the second quarter to $38.2 billion.

That surge in inventory came as revenue at its online stores, which make up the bulk of Amazon's inventory, fell 4% to $50.9 billion. In other words, Amazon is facing the same problem as the rest of the industry. It has more stuff than it can sell, especially with holiday orders about to roll in, so clearing out merchandise ahead of the holiday season with another Prime Day makes sense.

There are other signs that Amazon's growth isn't living up to expectations. The company recently closed or abandoned plans for 42 warehouses, or nearly 25 million square feet, according to consulting firm MWPVL International. It also delayed opening 21 new facilities.

Several news outlets recently reported that the company has frozen hiring in its retail division, a sign that growth in its first-party retail business remains sluggish.

What it means for investors

Amazon's revenue grew just 7.2% in the second quarter, and its performance in e-commerce was even worse. Revenue increased 10% in North America, but fell 12% in its international segment. 

For the third quarter, the company expected sales growth to reaccelerate as comparisons with the period a year ago get easier, and it forecast overall top-line growth of 13% to 17%. However, the addition of the second Prime Day, as well as the hiring freeze and warehouse closures, indicate that its performance in Q3 may have disappointed. 

Similarly, if the company feels the need to hold a second Prime Day just before the holiday season, that's a good sign of upcoming markdowns, meaning that merchandise margins will be narrower than usual in the fourth quarter, impacting overall profitability.

For long-term investors, that's no reason to bail on the stock. After all, Amazon Web Services, its cloud infrastructure business, remains the main source of its profits, and that business continues to look strong.

However, considering the tech giant's bloated inventory, cutbacks in hiring and in its warehouses, and weakness in the macro-level economy, investors should be prepared for more turbulence ahead from the stock.