Because advertisers will use Gemini instead.
Advertisers already have established relationships and business processes with Google account managers.
Why bother starting from scratch with a new account manager at OpenAI? Will OpenAI even last?
At least Google has been around a while. Seems like a safer investment from point of view of advertiser.
I honestly don’t think open ai has the maturity or discipline for long-term viability, but their operating expenses for a week would eclipse the annual payroll required to hire a large corporate infrastructure that may be the best shot they have at transitioning from a company operating on hope and buzz to one that actually makes a few bucks. I’ll eat my hat if they become the next Google, but they didn’t pull the playbook out of thin air.
When you're working in ads, you don't have 1 person that looks after multiple huge clients.
If you have a Coke or a Nike or a McDonalds or an Apple etc spending 10s/100s of millions in ad spend on your platform, you have a dedicated whole team of 3 or 4 or 5 or more people (sales and dedicated tech support, plus managers etc) per client who exist solely to make it easy for that client to run ads on your platform, and make sure they're happy and getting results. So just those 4 clients you are probably looking at 20+ people just in sales/after-sales supporting 100+mil of ad spend, and that is before you need to support agencies like WPP et al that are often teams of 10 to 15 or more. And if a client doesn't think they're getting the results they need or the treatment they need, they'll take their ad spend elsewhere - this is why you have multiple sales people and hands-on tech people swarming the big spenders to keep them happy and keep them spending.
It is a huge undertaking to pivot to become a large-scale ad network. Not saying it is impossible, but it is not quick nor easy by any stretch, and should not be underestimated.
Genuinely their best bet is to start by selling ad slots via Google (and you can bet there will be a team of 10+ sales and tech support ready to support them exclusively within a few days if they do) while they build their own capability (if at all). Google ads will have better tracking and targeting and so better conversions than Open ai could do themselves due to the network effect of Google's existing online properties (e.g. YouTube, Search, Play etc), partner ad network, browser, and mobile dominance (despite what people on HN think, the "normal" people online do click on ads. This is why Google and Facebook are printing money).
They are competing directly against their biggest AI competitor who has better AI models than them (at the moment at least) which are SOTA, AND also has an existing huge ad business and sales force. Not to mention Google is currently cramming AI into every single one of their products and serving to billions of people already, and own their entire business from silicon up through to the properties people are advertising on.
OpenAI are coming from behind both in their AI tech, their DAU count, and in their advertising business (or rather lack of it). And they're doing this while actually renting hardware from Google Cloud to do it too!
Not impossible for them to do this of course, but it is a big lift and will take years. They might do it though, but I think odds are they'll fizzle out before then (either run out of money, enshitification, or simply fall to the back of the pack)
People who say "Google are toast" just don't understand the scale of the ads business (and the markets seem to agree that goog is insurmountable, at least for now)