A spokesperson for eBay confirmed the layoffs to Reuters on Wednesday, saying the move will eliminate around 1,000 jobs.
The company had 12,300 employees at the end of last year. It also let go about 6% of its workforce, or 800 employees, in February as part of efforts to streamline operations.
EBay has set itself apart from rivals by pushing into authenticated luxury goods, collectibles and refurbished products, which draw enthusiasts willing to pay more for valuable items. That has helped its shares rise nearly 40% this year, outperforming the benchmark S&P 500's around 12% gain.
"Our strategy is working," Iannone said in the memo, adding that "continuing to capture the significant opportunity ahead requires us to make thoughtful choices about where we focus and invest."
He said affected staff would be informed in the coming days.
Shares of eBay rose about 1% in early trading.
The company has this year also benefited from its $1.4 billion deal for fashion resale platform Depop, which expanded its reach among younger consumers and strengthened its position in the growing re-commerce market.
That helped eBay forecast third-quarter revenue above Wall Street estimates when it last posted results, in August. The company is slated to report latest earnings next week.
Those efforts have also caught the eye of GameStop CEO Ryan Cohen, who made an unsolicited $56 billion bid for the much larger eBay in May. EBay had rejected the offer, saying that it was "neither credible nor attractive."