Amazon's advertising business grew 19% in the third quarter

Amazon's online advertising business brought in $14.3 billion in the third quarter, up 19% year over year, in line with analysts' estimates of $14.3 billion.

The Seattle tech giant revealed the financial results of its growing advertising unit as part of its latest earnings report Thursday. Amazon's overall third-quarter sales were $158.9 billion, ahead of analysts' estimates of $157.2 billion.

Amazon's online advertising business is still a fraction of the company's overall business, but its growth over the years has made it a major competitor to Alphabet and Meta, which lead the digital advertising market. Alphabet's Google currently represents 27.7% of the worldwide digital advertising market, followed by Meta at 22.8% and Amazon with 8.8%, according to data provided to CNBC by Emarketer.

Meta's third-quarter advertising revenue came in at $39.9 billion, which was up 19% compared with the year prior. That was slightly ahead of analysts' expectations of $39.49 billion, according to StreetAccount. Ads accounted for 98.3% of Meta's overall third-quarter revenue.

Alphabet generated $65.85 billion in third-quarter ad revenue, the company reported Tuesday. That was up 10% from $59.65 billion the year prior. Additionally, advertising sales for the company's YouTube unit rose 12% year over year to $8.92 billion.

Microsoft's search and news advertising revenue increased 18% year over year in the company's latest quarterly earnings report Wednesday. Microsoft does not disclose its advertising unit's specific quarterly sales figures.

Social media companies Snap and Reddit reported their latest earnings Tuesday. Reddit said its third-quarter sales rose 68% year over year to $348.4 million, while Snap said its third-quarter revenue was