EBay Inc. is set to report its third-quarter earnings after the stock market closes on Wednesday.

WHAT TO WATCH FOR: EBay has already predicted revenue and adjusted earnings slightly below what it reported in last year's third quarter, so investors will keep an eye out for any growth in eBay's online marketplace and PayPal online payments business.

EBay, which is based in San Jose, has been rolling out continuous changes to in hopes of enticing buyers and retaining sellers; it has cut upfront fees it charges sellers and modified its search technology in hopes of giving users increasingly relevant results.

PayPal has grown rapidly even as has stumbled, and it's likely that its momentum kept up in the third quarter as merchants and consumers used it on and off eBay's namesake site.

Mobile is quickly becoming an important part of eBay's strategy — the company now offers an array of eBay and PayPal applications for devices such as Apple's iPhone and iPad and phones that run Google's Android operating software. EBay may indicate how mobile is helping its business, and how this could change in the future.

WHY IT MATTERS: As a large e-commerce company, eBay's success can be indicative of how other online retailers and auction websites are faring.

WHAT'S EXPECTED: In July, eBay forecast an adjusted profit of 35 cents to 37 cents per share on $2.13 billion to $2.18 billion in revenue. The company said in September that it expected to report near the top of this range.

Analysts polled by Thomson Reuters, who typically exclude one-time items, on average expect an adjusted profit of 37 cents per share on $2.18 billion in revenue.

LAST YEAR'S QUARTER: In the third quarter of 2009, eBay earned $350 million, or 27 cents per share, on $2.24 billion in revenue. Excluding one-time items, eBay earned 38 cents per share.