Published by on November 21, 2016

Twitter’s Chief Operating Officer, Adam Bain, the man who has been largely responsible for the rapid growth and recent slowdown in Twitter’s ad business, is to leave the company.

The news was originally reported by the New York Times earlier this month, and was then confirmed by the man himself, who tweeted that after six years, he is ready to take on a new challenge. The company subsequently filed a notice with the Securities and Exchange Commission (SEC) that Bain had handed in his resignation.

It is believed that Bain will be staying on at the company until at least the end of November, but according to a Twitter spokesperson, Chief Financial Officer Anthony Noto will be taking over Bain’s position, while continuing in his current role until a replacement is found. Noto has a banking background, but has been involved in handling some of the company’s marketing projects, and has previously fielded ad business-related questions from analysts.

Under Bain’s guidance, Twitter’s ad business has seen rapid growth throughout most of his tenure, but that growth has slowed in recent months. Earlier this year, the company announced that it was laying off 350 members of staff, with most of those departures concentrated in the company’s ad sales and marketing departments.

But despite the slowdown, Twitter’s ad business remains strong compared to some of its main rivals. At the same time that Facebook has had to admit that it may be approaching a ceiling on its ad load, Twitter has actually been able to decrease ad load in the third quarter of 2016, while still taking more revenue from its ad business than in quarter two, suggesting that the company is still growing and is getting better at targeting its advertising.

At this stage, no-one knows where Bain is likely to end up. A deeply popular figure within the company, he has many admirers in the US advertising industry, so will not be short of offers, but it is understood that he has assured executives at Twitter that he has no intention of joining one of the company’s social media rivals.