am curious if tesla, or any musk-related concerns, run ads on X ?

Yes, Tesla has said it ran $200,000 in ads on X. That’s a pretty trivial amount actually, given that some of their former advertisers were spending 7 figures or more. You would think they would run tons of ads, especially since the demand is so low from other advertisers but they’re not.

One wrinkle, which I do not fully understand, is that revenues from commonly owned businesses for such things have to be segregated out when reporting for public companies, lest companies inflate their true revenues and deceive shareholders. I note that I see ads for Disney+ on ABC and for Peacock on NBC and Paramount+ on CBS, so I don’t know exactly what’s going on, but I do have an example:

In the 1990’s I was at KDKA Radio and we had an ad campaign we wanted to saturate the marketplace, and KDKA TV was astonishingly strong, so we “bought” a schedule (maybe $50,000) there in addition to several hundred thousand dollars on other TV stations, and shortly before the flight ended we got called on the carpet by the Westinghouse lawyers, upbraiding us for all the extra work that was going to entail, the accounting baloney that would have to be included in the annual report, blah blah blah.

(Recall that Westinghouse was the 4th largest broadcaster in the country with 7 AM, 7FM, 5 TV, and a host of other allied businesses including satellite backhaul (half the cable industry used us for distribution), syndication (everything from Mike Douglas & Merv Griffin to Teenage Mutant Ninja Turtles), and partial ownership in production companies like Castle Rock. And we were causing “a headache” by funneling money from one corporate pocket to another. Like if we dropped a poker chip at the gaming table.

I don’t know if those rules have changed or been relaxed, I’ve been out for 25 years, but there may be some arcane reason Tesla doesn’t do more. Or maybe they think they don’t need to, even though there are reports of inventory stacking up at shopping malls and empty fields.