If one single factor has made Twitter vulnerable to Elon Musk’s takeover attempt, it’s the lagging performance of its ad business compared with those of its rivals. Consider that when Snap started seriously selling ads in its messaging app in 2015, Twitter’s ad business was already producing more than $2 billion in revenue annually. By the first quarter of this year, the ad businesses of the two social media companies were roughly equal, as Twitter’s results released on Thursday demonstrated.

One major reason why Twitter has grown so much slower than Snap is that Twitter failed to build the technology necessary to run effective direct-response ad campaigns, ad executives say. That means the company hasn’t been able to compete for the direct-response ad money pouring into rivals like Meta Platforms and Snap.

“It’s not that they didn’t build one. They did; it’s just a bad one. If the product was good, the dollars would be there,” said Kevin Simonson, who used to run a performance marketing agency. Simonson said he was recently served an ad on Twitter in Spanish for a grill. His default language is set as English. “That experience is horrible,” he said.