Tried it early on. The targeting is still pretty blunt compared to LinkedIn or even Google for B2B. You're essentially betting on intent signals from the query rather than firmographic data, which works better for some verticals than others.
What made the most difference for me was being specific about the problem the user is searching for rather than leading with what you sell. ChatGPT users are in solution-seeking mode, so if your ad copy matches the frame of the question they're asking, you get better clicks. Generic "we help B2B companies grow" copy lands flat there.
The honest take: it's worth a small test budget to understand the channel, but I wouldn't pull spend from LinkedIn if you're running it for lead gen with any precision targeting. The CPL is hard to defend right now unless your deal size is large enough that a few qualified clicks pay for the whole experiment.
What industry are you in? Makes a difference whether it's worth the setup time.