Former NBCU ad exec Linda Yaccarino’s tenure at X may have been fairly short — just two years from start to finish — but she did manage to make an impact on the social network’s ad business, new data from ad intelligence firm Guideline shows. Yaccarino will be leaving X in a better position with its advertisers than she found it, it says.

In the U.S., ad spending was up 62% year-over-year in the first half of 2025, Guideline notes. In addition, Yaccarino previously claimed that 96% of X’s advertisers returned to X as of May 2025.

However, it took time for X’s advertising business to turn around, and it remains a turbulent business.

Yaccarino’s departure could have a significant impact on X’s profitability, as the company is nowhere near ready to rely entirely on other revenue streams. Its X Premium subscriptionsfor example, only account for a small portion of its business, and it hasn’t yet launched its broader ambitions around an X Money payments service.

Yaccarino first joined X in June 2023 after spending nearly 12 years at NBCUniversal, where she had been chairman of global advertising and partnerships. At the time, X (then called Twitter) was facing a critical advertising downturn.

Many of the initial cuts to ad spend were prompted by Elon Musk’s takeover of the network in October 2022. With cuts to Twitter staff, including its Trust and Safety divisionmisinformation and hate speech proliferated — which advertisers wanted nothing to do with. Reuters noted that 14 of the 30 top advertisers stopped all their advertising on the platformand four advertisers had reduced their spending from 92% to 98.7% around that time.

Guideline’s data found that 89% of Twitter/X’s U.S. ad dollars were eroded in the two years between Q3 2022 and Q3 2024. (These declines had actually begun in Q2 2022, after it was revealed that Musk bought a 9.4% stake in the company, the firm told TechCrunch via email.)

By early 2023, reports surfaced that more than 500 of Twitter’s advertisers had left the platform, and fourth-quarter revenues dropped by 35%.

Citing internal documents, The New York Times reported that the social network’s U.S. ad business was down 59% from a year earlierfrom the five weeks between April 1 and the first week of May 2023, reaching $88 million. Its weekly sales projections were also down by as much as 30%. X then tried luring advertisers back with ad credits.

There were hints that Yaccarino was working behind the scenes to repair things, though.

A year after she joined X, the Times reported that 65% of advertisers had returnedciting recordings of internal meetings at the company. In August 2023, Yaccarino claimed that X’s operational run rate was close to “break even.”

But the situation worsened again that year with an advertiser boycott.

In November 2023, brands including Apple, Disney, and IBM paused their ad spending on X in the wake of Musk’s endorsement of an antisemitic post. The social network was already on track for a nearly 55% year-over-year decline in worldwide ad spending, according to eMarketer estimates, and this boycott threatened to worsen the situation further.

Musk had also been a challenge for Yaccarino during her time with the company. The X owner and SpaceX exec famously told X advertisers leaving to “go fuck yourself,” calling their departure a form of blackmail. When cursing at them didn’t work, X sued insteadsaying theirs was an “illegal boycott.” (The suit was expanded in early 2025 to include more advertisers, such as LEGO and Shell.)

The threat of litigation worked — companies including Verizon and Ralph Lauren resumed advertising on the platform after receiving legal threatsThe Wall Street Journal reported in June 2025. The World Federation of Advertisers (WFA) also suspended the operations of its Global Alliance for Responsible Media (GARM) nonprofit after the lawsuit was filed against it.

Guideline’s data also indicates that X has seen increased U.S. ad spend since December 2024 — the first time since Musk bought the company, it says. From Q3 2024 to Q4 2024, spending was up 37.7%, influenced by the U.S. presidential elections.

During Yaccarino’s time, X also made moves to ensure more brand safety, partnering with adtech companies DoubleVerify and Integral Ad Science (IAS) to warn them if ads were placed around inappropriate content. It also offered brands tools to adjust the sensitivity of where their ads were displayed on the app, where more “relaxed” ad slots would cost less, and those with higher safety concerns would pay more. Later, X introduced ways for advertisers to run their ads next to a curated set of content creators.

None of this has stopped X from being a controversial platform with regard to ad safety.

This week, for instance, the site’s AI bot Grok went off the rails after experiencing antisemitic outbursts requiring X to take it offline. Now, instead of facing another ad crisis, Yaccarino is leaving — although her decision was reportedly made prior to the Grok incident.