Anthropic spent Sunday night’s Super Bowl bashing OpenAI for planning to introduce ads to ChatGPT through a series of tongue-in-cheek ads. Then, just a few hours later, ChatGPT officially opened the ads.

Starting Monday, logged-in mature users of the Free and Go subscription levels will begin seeing test ads on ChatGPT, while other paid subscriptions will be spared, at least for now.

“Ads do not influence the responses ChatGPT gives you, and we keep your ChatGPT conversations private from advertisers,” OpenAI said in a press release, but what ads you get will be influenced by your past chats. “We started a test to learn, listen, and make sure we get the experience right.”

For days now, the internet has boisterous saba about four ads that Anthropic launched for the Super Bowl. Each ad includes a different person consulting a personified AI chatbot, only to be met strange and, sometimes, inappropriate ads masquerading as advice. All ads end with “Ads are coming to AI. But not to Claude.”

This is a clear dig at OpenAI, which first officially teased an ads business model for ChatGPT in an internal “code red” memo back in December.

OpenAI CEO Sam Altman responded to Anthropic’s ads on Twitter last week, calling them “funny” but “clearly disingenuous.”

“Obviously we will not be running the ads the way Anthropic describes them,” Altman wrote. He admitted that an ad business would make ChatGPT’s free offering financially sustainable for the business, which still faces a uncertainty road to profit. Those who pay for a ChatGPT Plus or Pro subscription will not be shown any ads.

“More Texans use ChatGPT for free than the total number of people using Claude in the US, so we have a different form of problem than they do,” Altman wrote, before going on to accuse Anthropic of serving “an expensive product to rich people” (Anthropic also has a free Claude offering) and wanting to “control what people do with AI.”

“Now they also want to tell other companies what their business models can do,” Altman said.

OpenAI and Anthropic rarely meet. Anthropic co-founders Dario and Daniela Amodei are both former employees of OpenAI who did not hold back the acquisition public jabs to their former employer. Dario Amodei is also quick evangelism about the risks of AI superintelligence, while Altman took it a bit further excited approach the idea. Employees of OpenAI and Anthropic are also reportedly returning both super PACs completely against AI regulation. Now it looks like we can add chatbot ads to this list of disagreements as well.

ChatGPT ads will be “clearly marked as sponsored and visually separated” from the response, OpenAI said.

There are also said to be some safeguards in place, such that although ads will be targeted to you based on your chat history, advertisers will not be able to access it, and ads will not appear near “sensitive or regulated topics such as health, mental health or politics.”

But even ads that don’t influence responses or appear separately within the protections seem like too much for Anthropic.

“Such ads would also introduce an incentive to optimize for engagement—for the amount of time people spend using Claude and how often they return. These metrics don’t necessarily align with what’s actually helpful,” Anthropic wrote in a press release last week.

Even opt-in ad methods pose a risk that increases over time, Anthropic argues.

“The most useful AI interaction may be a brief one, or one that resolves the user’s request without prompting further conversation,” Anthropic said.

The inclusion of ads was a notable change in Altman’s thinking. Before the company’s executives started pitching the idea, Altman described “ads-plus-AI” as a “last resort,” and “kind of strangely unsettling.”