That was fast. Looking forward to the future where I ask for travel tips in a city and being told that I should stop by a McDonalds to have enough energy to explore said city - I'm loving it!
They'd lose trust being so overt. A more subtle influence is that your suggestions would include sites nearby a McD at the expense of ones that don't. After months of gathering sales data from McD they'd ring up Burger King to see if they'd like such suggestions to be tweaked. It would also suggest departure times so that you'd pass by the real target at typical feasting hours.
Lose less trust by being more deceptive --- the motto of modern institutions
subtle psyops, just to make money.
It wont even mention $great_site_1 because there's more profit for mcdonalds to send you to $mediocre_site_with_attached_burger
It's neat to think how these technologies could be the next step in soloing the internet further. Imagine google's AI preferentially directing you to websites that participate in Google advertising programs. You get a different internet depending on which AI you ask. Not that I think it's a sure thing but I definitely don't see it as unlikely either.
We might live in a world where you are a GPT-4 bot pretending to be a real person for years, only to mention McDonalds in passing, in a seemingly negative fashion that still increases brand consciousness. I don't know if that's already the present, but it will be the future.